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The Security Outcomes Report: Adoption, Access, And Automation Trends shows that 86.5% of orgs have begun zero trust, only 2% reaching maturity.

Microsoft fixed three vulnerabilities that threat actors are exploiting, part of its' Patch Tuesday bug fix roundup.

SUMMARY The Federal Bureau of Investigation (FBI) and Cybersecurity and Infrastructure Security Agency (CISA) are releasing this joint Cybersecurity Advisory (CSA) in response to recent activity by Scattered Spider threat actors against the commercial facilities sectors and subsectors. This advisory provides tactics, techniques, and procedures (TTPs) obtained through FBI investigations as recently as November 2023. Scattered Spider is a cybercriminal group that targets large companies and their contracted information technology (IT) help desks. Scattered Spider threat actors, per trusted third parties, have typically engaged in data theft for extortion and have also been known to utilize BlackCat/ALPHV ransomware alongside their usual TTPs. The FBI and CISA encourage critical infrastructure organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of a cyberattack by Scattered Spider actors. Download the PDF version of this report: A23-320A Scattered Spider (PDF, 517.03 KB ) TECHNICAL DETAILS Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 14. See the MITRE ATT&CK ® Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool. Overview Scattered Spider (also known as Starfraud, UNC3944, Scatter Swine, and Muddled Libra) engages in data extortion and several other criminal activities.[ 1] Scattered Spider threat actors are considered experts in social engineering and use multiple social engineering techniques, especially phishing, push bombing, and subscriber identity module (SIM) swap attacks, to obtain credentials, install remote access tools, and/or bypass multi-factor authentication (MFA). According to public reporting, Scattered Spider threat actors have [ 2],[ 3],[ 4]: Posed as company IT and/or helpdesk staff using phone calls or SMS messages to obtain credentials from employees and gain access to the network [ T1598],[ T1656]. Posed as company IT and/or helpdesk staff to direct employees to run commercial remote access tools enabling initial access [ T1204],[ T1219],[ T1566]. Posed as IT staff to convince employees to share their one-time password (OTP), an MFA authentication code. Sent repeated MFA notification prompts leading to employees pressing the “Accept” button (also known as MFA fatigue) [ T1621].[ 5] Convinced cellular carriers to transfer control of a targeted user’s phone number to a SIM card they controlled, gaining control over the phone and access to MFA prompts. Monetized access to victim networks in numerous ways including extortion enabled by ransomware and data theft [ T1657]. After gaining access to networks, FBI observed Scattered Spider threat actors using publicly available, legitimate remote access tunneling tools. Table 1 details a list of legitimate tools Scattered Spider, repurposed and used for their criminal activity. Note: The use of these legitimate tools alone is not indicative of criminal activity. Users should review the Scattered Spider indicators of compromise (IOCs) and TTPs discussed in this CSA to determine whether they have been compromised. Table 1: Legitimate Tools Used by Scattered Spider Tool Intended Use Fleetdeck.io Enables remote monitoring and management of systems. Level.io Enables remote monitoring and management of systems. Mimikatz [ S0002] Extracts credentials from a system. Ngrok [ S0508] Enables remote access to a local web server by tunneling over the internet. Pulseway Enables remote monitoring and management of systems. Screenconnect Enables remote connections to network devices for management. Splashtop Enables remote connections to network devices for management. Tactical.RMM Enables remote monitoring and management of systems. Tailscale Provides virtual private networks (VPNs) to secure network communications. Teamviewer Enables remote connections to network devices for management. In addition to using legitimate tools, Scattered Spider also uses malware as part of its TTPs. See Table 2 for some of the malware used by Scattered Spider. Table 2: Malware Used by Scattered Spider Malware Use AveMaria (also known as WarZone [ S0670]) Enables remote access to a victim’s systems. Raccoon Stealer Steals information including login credentials [ TA0006], browser history [ T1217], cookies [ T1539], and other data. VIDAR Stealer Steals information including login credentials, browser history, cookies, and other data. Scattered Spider threat actors have historically evaded detection on target networks by using living off the land techniques and allowlisted applications to navigate victim networks, as well as frequently modifying their TTPs. Observably, Scattered Spider threat actors have exfiltrated data [ TA0010] after gaining access and threatened to release it without deploying ransomware; this includes exfiltration to multiple sites including U.S.-based data centers and MEGA[.]NZ [ T1567.002]. Recent Scattered Spider TTPs New TTP - File Encryption More recently, the FBI has identified Scattered Spider threat actors now encrypting victim files after exfiltration [ T1486]. After exfiltrating and/or encrypting data, Scattered Spider threat actors communicate with victims via TOR, Tox, email, or encrypted applications. Reconnaissance, Resource Development, and Initial Access Scattered Spider intrusions often begin with broad phishing [ T1566] and smishing [ T1660] attempts against a target using victim-specific crafted domains, such as the domains listed in Table 3 [ T1583.001]. Table 3: Domains Used by Scattered Spider Threat Actors Domains victimname-sso[.]com victimname-servicedesk[.]com victimname-okta[.]com In most instances, Scattered Spider threat actors conduct SIM swapping attacks against users that respond to the phishing/smishing attempt. The threat actors then work to identify the personally identifiable information (PII) of the most valuable users that succumbed to the phishing/smishing, obtaining answers for those users’ security questions. After identifying usernames, passwords, PII [ T1589], and conducting SIM swaps, the threat actors then use social engineering techniques [ T1656] to convince IT help desk personnel to reset passwords and/or MFA tokens [ T1078.002],[ T1199],[ T1566.004] to perform account takeovers against the users in single sign-on (SSO) environments. Execution, Persistence, and Privilege Escalation Scattered Spider threat actors then register their own MFA tokens [ T1556.006],[ T1606] after compromising a user’s account to establish persistence [ TA0003]. Further, the threat actors add a federated identity provider to the victim’s SSO tenant and activate automatic account linking [ T1484.002]. The threat actors are then able to sign into any account by using a matching SSO account attribute. At this stage, the Scattered Spider threat actors already control the identity provider and then can choose an arbitrary value for this account attribute. As a result, this activity allows the threat actors to perform privileged escalation [ TA0004] and continue logging in even when passwords are changed [ T1078]. Additionally, they leverage common endpoint detection and response (EDR) tools installed on the victim networks to take advantage of the tools’ remote-shell capabilities and executing of commands which elevates their access. They also deploy remote monitoring and management (RMM) tools [ T1219] to then maintain persistence. Discovery, Lateral Movement, and Exfiltration Once persistence is established on a target network, Scattered Spider threat actors often perform discovery, specifically searching for SharePoint sites [ T1213.002], credential storage documentation [ T1552.001], VMware vCenter infrastructure [ T1018], backups, and instructions for setting up/logging into Virtual Private Networks (VPN) [ TA0007]. The threat actors enumerate the victim’s Active Directory (AD), perform discovery and exfiltration of victim’s code repositories [ T1213.003], code-signing certificates [ T1552.004], and source code [ T1083],[ TA0010]. Threat actors activate Amazon Web Services (AWS) Systems Manager Inventory [ T1538] to discover targets for lateral movement [ TA0007],[ TA0008], then move to both preexisting [ T1021.007] and actor-created [ T1578.002] Amazon Elastic Compute Cloud (EC2) instances. In instances where the ultimate goal is data exfiltration, Scattered Spider threat actors use actor-installed extract, transform, and load (ETL) tools [ T1648] to bring data from multiple data sources into a centralized database [ T1074],[ T1530]. According to trusted third parties, where more recent incidents are concerned, Scattered Spider threat actors may have deployed BlackCat/ALPHV ransomware onto victim networks—thereby encrypting VMware Elastic Sky X integrated (ESXi) servers [ T1486]. To determine if their activities have been uncovered and maintain persistence, Scattered Spider threat actors often search the victim’s Slack, Microsoft Teams, and Microsoft Exchange online for emails [ T1114] or conversations regarding the threat actor’s intrusion and any security response. The threat actors frequently join incident remediation and response calls and teleconferences, likely to identify how security teams are hunting them and proactively develop new avenues of intrusion in response to victim defenses. This is sometimes achieved by creating new identities in the environment [ T1136] and is often upheld with fake social media profiles [ T1585.001] to backstop newly created identities. MITRE ATT&CK TACTICS AND TECHNIQUES See Tables 4 through 17 for all referenced threat actor tactics and techniques in this advisory. Table 4: Reconnaissance Technique Title ID Use Gather Victim Identity Information T1589 Scattered Spider threat actors gather usernames, passwords, and PII for targeted organizations. Phishing for Information T1598 Scattered Spider threat actors use phishing to obtain login credentials, gaining access to a victim’s network. Table 5: Resource Development Technique Title ID Use Acquire Infrastructure: Domains T1583.001 Scattered Spider threat actors create domains for use in phishing and smishing attempts against targeted organizations. Establish Accounts: Social Media Accounts T1585.001 Scattered Spider threat actors create fake social media profiles to backstop newly created user accounts in a targeted organization. Table 6: Initial Access Technique Title ID Use Phishing T1566 Scattered Spider threat actors use broad phishing attempts against a target to obtain information used to gain initial access. Scattered Spider threat actors have posed as helpdesk personnel to direct employees to install commercial remote access tools. Phishing (Mobile) T1660 Scattered Spider threat actors send SMS messages, known as smishing, when targeting a victim. Phishing: Spearphishing Voice T1566.004 Scattered Spider threat actors use voice communications to convince IT help desk personnel to reset passwords and/or MFA tokens. Trusted Relationship T1199 Scattered Spider threat actors abuse trusted relationships of contracted IT help desks to gain access to targeted organizations. Valid Accounts: Domain Accounts T1078.002 Scattered Spider threat actors obtain access to valid domain accounts to gain initial access to a targeted organization. Table 7: Execution Technique Title ID Use Serverless Execution T1648 Scattered Spider threat actors use ETL tools to collect data in cloud environments. User Execution T1204 Scattered Spider threat actors impersonating helpdesk personnel direct employees to run commercial remote access tools thereby enabling access to the victim’s network. Table 8: Persistence Technique Title ID Use Persistence TA0003 Scattered Spider threat actors seek to maintain persistence on a targeted organization’s network. Create Account T1136 Scattered Spider threat actors create new user identities in the targeted organization. Modify Authentication Process: Multi-Factor Authentication T1556.006 Scattered Spider threat actors may modify MFA tokens to gain access to a victim’s network. Valid Accounts T1078 Scattered Spider threat actors abuse and control valid accounts to maintain network access even when passwords are changed. Table 9: Privilege Escalation Technique Title ID Use Privilege Escalation TA0004 Scattered Spider threat actors escalate account privileges when on a targeted organization’s network. Domain Policy Modification: Domain Trust Modification T1484.002 Scattered Spider threat actors add a federated identify provider to the victim’s SSO tenant and activate automatic account linking. Table 10: Defense Evasion Technique Title ID Use Modify Cloud Compute Infrastructure: Create Cloud Instance T1578.002 Scattered Spider threat actors will create cloud instances for use during lateral movement and data collection. Impersonation TA1656 Scattered Spider threat actors pose as company IT and/or helpdesk staff to gain access to victim’s networks. Scattered Spider threat actors use social engineering to convince IT help desk personnel to reset passwords and/or MFA tokens. Table 11: Credential Access Technique Title ID Use Credential Access TA0006 Scattered Spider threat actors use tools, such as Raccoon Stealer, to obtain login credentials. Forge Web Credentials T1606 Scattered Spider threat actors may forge MFA tokens to gain access to a victim’s network. Multi-Factor Authentication Request Generation T1621 Scattered Spider sends repeated MFA notification prompts to lead employees to accept the prompt and gain access to the target network. Unsecured Credentials: Credentials in Files T1552.001 Scattered Spider threat actors search for insecurely stored credentials on victim’s systems. Unsecured Credentials: Private Keys T1552.004 Scattered Spider threat actors search for insecurely stored private keys on victim’s systems. Table 12: Discovery Technique Title ID Use Discovery TA0007 Upon gaining access to a targeted network, Scattered Spider threat actors seek out SharePoint sites, credential storage documentation, VMware vCenter, infrastructure backups and enumerate AD to identify useful information to support further operations. Browser Information Discovery T1217 Scattered Spider threat actors use tools (e.g., Raccoon Stealer) to obtain browser histories. Cloud Service Dashboard T1538 Scattered Spider threat actors leverage AWS Systems Manager Inventory to discover targets for lateral movement. File and Directory Discovery T1083 Scattered Spider threat actors search a compromised network to discover files and directories for further information or exploitation. Remote System Discovery T1018 Scattered Spider threat actors search for infrastructure, such as remote systems, to exploit. Steal Web Session Cookie T1539 Scattered Spider threat actors use tools, such as Raccoon Stealer, to obtain browser cookies. Table 13: Lateral Movement Technique Title ID Use Lateral Movement TA0008 Scattered Spider threat actors laterally move across a target network upon gaining access and establishing persistence. Remote Services: Cloud Services T1021.007 Scattered Spider threat actors use pre-existing cloud instances for lateral movement and data collection. Table 14: Collection Technique Title ID Use Data from Information Repositories: Code Repositories T1213.003 Scattered Spider threat actors search code repositories for data collection and exfiltration. Data from Information Repositories: Sharepoint T1213.002 Scattered Spider threat actors search SharePoint repositories for information. Data Staged T1074 Scattered Spider threat actors stage data from multiple data sources into a centralized database before exfiltration. Email Collection T1114 Scattered Spider threat actors search victim’s emails to determine if the victim has detected the intrusion and initiated any security response. Data from Cloud Storage T1530 Scattered Spider threat actors search data in cloud storage for collection and exfiltration. Table 15: Command and Control Technique Title ID Use Remote Access Software T1219 Impersonating helpdesk personnel, Scattered Spider threat actors direct employees to run commercial remote access tools thereby enabling access to and command and control of the victim’s network. Scattered Spider threat actors leverage third-party software to facilitate lateral movement and maintain persistence on a target organization’s network. Table 16: Exfiltration Technique Title ID Use Exfiltration TA0010 Scattered Spider threat actors exfiltrate data from a target network to for data extortion. Table 17: Impact Technique Title ID Use Data Encrypted for Impact T1486 Scattered Spider threat actors recently began encrypting data on a target network and demanding a ransom for decryption. Scattered Spider threat actors has been observed encrypting VMware ESXi servers. Exfiltration Over Web Service: Exfiltration to Cloud Storage T1567.002 Scattered Spider threat actors exfiltrate data to multiple sites including U.S.-based data centers and MEGA[.]NZ. Financial Theft T1657 Scattered Spider threat actors monetized access to victim networks in numerous ways including extortion-enabled ransomware and data theft. MITIGATIONS These mitigations apply to all critical infrastructure organizations and network defenders. The FBI and CISA recommend that software manufactures incorporate secure-by-design and -default principles and tactics into their software development practices limiting the impact of ransomware techniques, thus, strengthening the secure posture for their customers. For more information on secure by design, see CISA’s Secure by Design and Default webpage and joint guide. The FBI and CISA recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture based on the threat actor activity and to reduce the risk of compromise by Scattered Spider threat actors. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections. Implement application controls to manage and control execution of software, including allowlisting remote access programs. Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation. Reduce threat of malicious actors using remote access tools by: Auditing remote access tools on your network to identify currently used and/or authorized software. Reviewing logs for execution of remote access software to detect abnormal use of programs running as a portable executable [ CPG 2.T ]. Using security software to detect instances of remote access software being loaded only in memory. Requiring authorized remote access solutions to be used only from within your network over approved remote access solutions, such as virtual private networks (VPNs) or virtual desktop interfaces (VDIs). Blocking both inbound and outbound connections on common remote access software ports and protocols at the network perimeter. Applying recommendations in the Guide to Securing Remote Access Software. Implementing FIDO/WebAuthn authentication or Public Key Infrastructure (PKI)-based MFA. These MFA implementations are resistant to phishing and not suspectable to push bombing or SIM swap attacks, which are techniques known to be used by Scattered Spider actors. See CISA’s fact sheet Implementing Phishing-Resistant MFA for more information. Strictly limit the use of Remote Desktop Protocol (RDP) and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [ CPG 2.W]: Audit the network for systems using RDP. Close unused RDP ports. Enforce account lockouts after a specified number of attempts. Apply phishing-resistant multifactor authentication (MFA) . Log RDP login attempts. In addition, the authoring authorities of this CSA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques, and to reduce the impact and risk of compromise by ransomware or data extortion actors: Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud). Maintain offline backups of data and regularly maintain backup and restoration (daily or weekly at minimum). By instituting this practice, an organization limits the severity of disruption to its business practices [ CPG 2.R]. Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST's standards for developing and managing password policies. Use longer passwords consisting of at least eight characters and no more than 64 characters in length [ CPG 2.B]. Store passwords in hashed format using industry-recognized password managers. Add password user “salts” to shared login credentials. Avoid reusing passwords [ CPG 2.C]. Implement multiple failed login attempt account lockouts [ CPG 2.G]. Disable password “hints.” Refrain from requiring password changes more frequently than once per year. Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher. Require administrator credentials to install software. Require phishing-resistant multifactor authentication (MFA) for all services to the extent possible, particularly for webmail, virtual private networks (VPNs), and accounts that access critical systems [ CPG 2.H]. Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Prioritize patching known exploited vulnerabilities in internet-facing systems [ CPG 1.E]. Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement [ CPG 2.F]. Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic and activity, including lateral movement, on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host [ CPG 3.A]. Install, regularly update, and enable real time detection for antivirus software on all hosts. Disable unused ports and protocols [ CPG 2.V ]. Consider adding an email banner to emails received from outside your organization [ CPG 2.M]. Disable hyperlinks in received emails. Ensure all backup data is encrypted, immutable (i.e., ensure backup data cannot be altered or deleted), and covers the entire organization’s data infrastructure [ CPG 2.K, 2.L, 2.R]. VALIDATE SECURITY CONTROLS In addition to applying mitigations, FBI and CISA recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The FBI and CISA recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory. To get started: Select an ATT&CK technique described in this advisory (see Tables 4-17). Align your security technologies against the technique. Test your technologies against the technique. Analyze your detection and prevention technologies’ performance. Repeat the process for all security technologies to obtain a set of comprehensive performance data. Tune your security program, including people, processes, and technologies, based on the data generated by this process. FBI and CISA recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory. REPORTING FBI and CISA are seeking any information that can be shared, to include a sample ransom note, communications with Scattered Spider group actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office, report the incident to the FBI Internet Crime Complaint Center (IC3) at IC3.gov, or CISA via CISA’s 24/7 Operations Center ( report@cisa.gov or 888-282-0870). REFERENCES [1] MITRE ATT&CK – Scattered Spider [2] Trellix - Scattered Spider: The Modus Operandi [3] Crowdstrike - Not a SIMulation: CrowdStrike Investigations Reveal Intrusion Campaign Targeting Telco and BPO Companies [4] Crowdstrike - SCATTERED SPIDER Exploits Windows Security Deficiencies with Bring-Your-Own-Vulnerable-Driver Tactic in Attempt to Bypass Endpoint Security [5] Malwarebytes - Ransomware group steps up, issues statement over MGM Resorts compromise DISCLAIMER The information in this report is being provided “as is” for informational purposes only. FBI and CISA do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI and CISA. VERSION HISTORY November 16, 2023: Initial version.

Today, the Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) released a joint Cybersecurity Advisory (CSA) on Scattered Spider—a cybercriminal group targeting commercial facilities sectors and subsectors. The advisory provides tactics, techniques, and procedures (TTPs) obtained through FBI investigations as recently as November 2023. Scattered Spider threat actors typically engage in data theft for extortion using multiple social engineering techniques and have recently leveraged BlackCat/ALPHV ransomware alongside their usual TTPs. FBI and CISA encourage network defenders and critical infrastructure organizations to review the joint CSA for recommended mitigations to reduce the likelihood and impact of a cyberattack by Scattered Spider actors. For more information, visit StopRansomware and see the updated #StopRansomware Guide.

Citrix has released security updates addressing vulnerabilities in Citrix Hypervisor 8.2 CU1 LTSR. A cyber threat actor could exploit these vulnerabilities to take control of an affected system. CISA encourages users and administrators to review Citrix Hypervisor Security Bulletin for CVE-2023-23583 and CVE-2023-46835 and apply the necessary updates.

View CSAF 1. EXECUTIVE SUMMARY CVSS v3 10.0 ATTENTION: Exploitable remotely/low attack complexity Vendor: Red Lion Equipment: Sixnet RTU Vulnerabilities: Authentication Bypass using an Alternative Path or Channel, Exposed Dangerous Method or Function 2. RISK EVALUATION Successful exploitation of these vulnerabilities could allow an unauthenticated attacker to execute commands with high privileges. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following Red Lion products are affected: ST-IPm-8460: Firmware 6.0.202 and later ST-IPm-6350: Firmware version 4.9.114 and later VT-mIPm-135-D: Firmware version 4.9.114 and later VT-mIPm-245-D: Firmware version 4.9.114 and later VT-IPm2m-213-D: Firmware version 4.9.114 and later VT-IPm2m-113-D: Firmware version 4.9.114 and later 3.2 Vulnerability Overview 3.2.1 AUTHENTICATION BYPASS USING AN ALTERNATIVE PATH OR CHANNEL CWE-288 Red Lion SixTRAK and VersaTRAK Series RTUs with authenticated users enabled (UDR-A) any Sixnet UDR message will meet an authentication challenge over UDP/IP. When the same message is received over TCP/IP the RTU will simply accept the message with no authentication challenge. CVE-2023-42770 has been assigned to this vulnerability. A CVSS v3 base score of 10.0 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). 3.2.2 EXPOSED DANGEROUS METHOD OR FUNCTION CWE-749 When user authentication is not enabled the shell can execute commands with the highest privileges. Red Lion SixTRAK and VersaTRAK Series RTUs with authenticated users enabled (UDR-A) any Sixnet UDR message will meet an authentication challenge over UDP/IP. When the same message comes over TCP/IP the RTU will simply accept the message with no authentication challenge. CVE-2023-40151 has been assigned to this vulnerability. A CVSS v3 base score of 10.0 has been calculated; the CVSS vector string is ( AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: United States 3.4 RESEARCHER Nitsan Litov of Claroty Research - Team82 reported these vulnerabilities to CISA. 4. MITIGATIONS Red Lion recommends users apply the latest patches to their products. Red Lion recommends users apply additional mitigations to help reduce the risk: Enable user authentication, see Red Lion instructions. Blocking all or most Sixnet UDR messages over TCP/IP will eliminate authentication bypass. Sixnet UDR messages over TCP/IP will be ignored. To block all Sixnet UDR messages over TCP/IP install Patch1_tcp_udr_all_blocked.tar.gz. ST-IPm-8460 – Install 8313_patch1_tcp_udr_all_blocked.tar.gz ST-IPm-6350/VT-mIPm-245-D/VT-mIPm-135-D/VT-IPm2m-213-D/VT-IPm2m-113-D – Install 855_patch1_tcp_udr_all_blocked.tar.gz To block all Sixnet UDR messages except I/O commands over TCP/IP and UDP/IP install Patch2_io_open.tar.gz. ST-IPm-8460 – Install 8313_patch2_io_open.tar.gz ST-IPm-6350/VT-mIPm-245-D/VT-mIPm-135-D/VT-IPm2m-213-D/VT-IPm2m-113-D – Install 855_patch2_io_open.tar.gz To Block all Sixnet UDR messages over TCP/IP: Enable iptables rules to block TCP/IP traffic. In the Sixnet I/O Tool Kit go to Configuration>Configuration Station/Module>"Ports" tab>Security. Select the "Load the this file with each station load" radio button to load a custom rc.firewall configuration file. The rules below will allow all other traffic except Sixnet UDR over TCP/IP. Please Note: Two rules that are added in by default were removed because they will block all traffic going into the interface. Remove these rules from the default rc.firewall file: iptables -P INPUT DROP (Drops everything coming in) iptables -P FORWARD DROP (Drops everything in FORWARD chain) Add one DROP rule which will drop all TCP/IP packet coming on UDR port 1594 by typing the following commands: insmodip_tables (Initialization) insmodiptable_filter (Initialization) insmodip_conntrack (Initialization) insmodiptable_nat (Initialization) iptables -F INPUT (Flushes INPUT chain) iptables -F OUTPUT (Flushes OUTPUT chain) iptables -F FORWARD (Flushes FORWARD chain) iptables -Z (Zero counters) iptables -P OUTPUT ACCEPT (Drops everything coming in, everything in FORWARD chain, and accepts everything going out) iptables -A INPUT -p tcp --dport 1594 -j DROP (Allows local traffic and blocks all TCP traffic coming from 1594) For installation instructions see Red Lion's support page. For more information, please refer to Red Lion’s security bulletin. CISA recommends users take defensive measures to minimize the risk of exploitation of this these vulnerabilities, such as: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting this these vulnerabilities has been reported to CISA at this time. 5. UPDATE HISTORY November 16, 2023: Initial Publication

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 6.8 ATTENTION: Exploitable remotely Vendor: Siemens Equipment: Mendix 7, Mendix 8, Mendix 9, Mendix 10 Vulnerability: Authentication Bypass by Capture-Replay 2. RISK EVALUATION Successful exploitation of this vulnerability could allow authenticated attackers to access or modify objects without proper authorization or escalate privileges in the context of the vulnerable app. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following versions of Siemens Mendix Applications, are affected: Mendix Applications using Mendix 7: all versions prior to V7.23.37 Mendix Applications using Mendix 8: all versions prior to V8.18.27 Mendix Applications using Mendix 9: all versions prior to V9.24.10 Mendix Applications using Mendix 10: all versions prior to V10.4.0 3.2 Vulnerability Overview 3.2.1 AUTHENTICATION BYPASS BY CAPTURE-REPLAY CWE-294 A capture-replay flaw in the platform could have an impact to apps built with the platform, if certain preconditions are met that depend on the app's model and access control design. This could allow authenticated attackers to access or modify objects without proper authorization, or escalate privileges in the context of the vulnerable app. CVE-2023-45794 has been assigned to this vulnerability. A CVSS v3 base score of 6.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Multiple COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens reported this vulnerability to CISA. 4. MITIGATIONS Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk: Mendix Applications using Mendix 7: Update to V7.23.37 or later version and redeploy your application Mendix Applications using Mendix 8: Update to V8.18.27 or later version and redeploy your application Mendix Applications using Mendix 9: Update to V9.24.10 or later version and redeploy your application Mendix Applications using Mendix 10: Update to V10.4.0 or later version and redeploy your application As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals. Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage For more information see the associated Siemens security advisory SSA-084182 in HTML and CSAF. CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability has a high attack complexity. 5. UPDATE HISTORY November 16, 2023: Initial Publication

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 7.5 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: OPC UA Modeling Editor (SiOME) Vulnerability: Improper Restriction of XML External Entity Reference 2. RISK EVALUATION Successful exploitation of this vulnerability could allow an attacker to interfere with an application's processing of XML data and read arbitrary files in the system. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS The following versions of Siemens OPC UA Modeling Editor (SiOME), are affected: OPC UA Modelling Editor (SiOME): versions prior to V2.8 3.2 Vulnerability Overview 3.2.1 IMPROPER RESTRICTION OF XML EXTERNAL ENTITY REFERENCE CWE-611 Affected products suffer from a XML external entity (XXE) injection vulnerability. This vulnerability could allow an attacker to interfere with an application's processing of XML data and read arbitrary files in the system. CVE-2023-46590 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Multiple COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens reported this vulnerability to CISA. 4. MITIGATIONS Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk: Siemens OPC UA Modelling Editor (SiOME): Update to V2.8 or later version As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals. Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage. For more information see the associated Siemens security advisory SSA-197270 in HTML and CSAF. CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. 5. UPDATE HISTORY November 16, 2023: Initial Publication

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 9.8 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: SIPROTEC 4 7SJ66 Vulnerabilities: Classic Buffer Overflow, Session Fixation, NULL Pointer Dereference, Origin Validation Error, Race Condition, Missing Release of Memory after Effective Lifetime 2. RISK EVALUATION Successful exploitation of these vulnerabilities could allow an attacker to execute a variety of exploits for the purpose of denial-of-service, data extraction, remote code execution, etc. 3. TECHNICAL DETAILS 3.1 AFFECTED PRODUCTS Siemens reports that the following SIPROTEC products are affected due to vulnerabilities in the underlying Wind River VxWorks network stack: SIPROTEC 4 7SJ66: versions prior to V4.41 3.2 Vulnerability Overview 3.2.1 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 Wind River VxWorks has a buffer overflow in the TCP component (issue 1 of 4). This is a IPNET security vulnerability: TCP Urgent Pointer = 0 that leads to an integer underflow. CVE-2019-12255 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.2 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 Wind River VxWorks 6.9 and vx7 has a buffer overflow in the IPv4 component. There is an IPNET security vulnerability: Stack overflow in the parsing of IPv4 packets' IP options. CVE-2019-12256 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.3 SESSION FIXATION CWE-384 Wind River VxWorks 6.6 through vx7 has session fixation in the TCP component. This is a IPNET security vulnerability: DoS of TCP connection via malformed TCP options. CVE-2019-12258 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). 3.2.4 NULL POINTER DEREFERENCE CWE-476 Wind River VxWorks 6.6, 6.7, 6.8, 6.9 and vx7 has an array index error in the IGMPv3 client component. There is an IPNET security vulnerability: DoS via NULL dereference in IGMP parsing. CVE-2019-12259 has been assigned to this vulnerability. A CVSS v3 base score of 7.5 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). 3.2.5 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 Wind River VxWorks 6.9 and vx7 has a buffer overflow in the TCP component (issue 2 of 4). This is an IPNET security vulnerability: TCP Urgent Pointer state confusion caused by a malformed TCP AO option. CVE-2019-12260 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.6 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 Wind River VxWorks 6.7 though 6.9 and vx7 has a buffer overflow in the TCP component (issue 3 of 4). This is an IPNET security vulnerability: TCP Urgent Pointer state confusion during connect () to a remote host. CVE-2019-12261 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.7 ORIGIN VALIDATION ERROR CWE-346 Wind River VxWorks 6.6, 6.7, 6.8, 6.9 and 7 has incorrect access control in the RARP client component. IPNET security vulnerability: Handling of unsolicited Reverse ARP replies (Logical Flaw). CVE-2019-12262 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.8 CONCURRENT EXECUTION USING SHARED RESOURCE WITH IMPROPER SYNCHRONIZATION ('RACE CONDITION') CWE-362 Wind River VxWorks 6.9.4 and vx7 has a buffer overflow in the TCP component (issue 4 of 4). There is an IPNET security vulnerability: TCP Urgent Pointer state confusion due to race condition. CVE-2019-12263 has been assigned to this vulnerability. A CVSS v3 base score of 8.1 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.9 MISSING RELEASE OF MEMORY AFTER EFFECTIVE LIFETIME CWE-401 Wind River VxWorks 6.5, 6.6, 6.7, 6.8, 6.9.3 and 6.9.4 has a memory leak in the IGMPv3 client component. There is an IPNET security vulnerability: IGMP Information leak via IGMPv3 specific membership report. CVE-2019-12265 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens ProductCERT reported these vulnerabilities to CISA. 4. MITIGATIONS Siemens has released a new version (V4.41 or later version) for SIPROTEC 4 7SJ66 and recommends users update to the latest version. As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals. Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage. For more information see the associated Siemens security advisory SSA-617233 in HTML and CSAF. CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as virtual private networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. 5. UPDATE HISTORY November 16, 2023: Initial Publication

As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). View CSAF 1. EXECUTIVE SUMMARY CVSS v3 9.8 ATTENTION: Exploitable remotely/low attack complexity Vendor: Siemens Equipment: SIMATIC MV500 Vulnerabilities: Classic Buffer Overflow, NULL Pointer Dereference, Improper Authentication, Inefficient Regular Expression Complexity, Excessive Iteration, Out-of-bounds Write 2. RISK EVALUATION Successful exploitation of these vulnerabilities could allow an attacker to achieve a denial-of-service condition, arbitrary code execution, or escalate privileges. 3.1 AFFECTED PRODUCTS The following products of Siemens, are affected: SIMATIC MV500 family: Versions prior to V3.3.5 3.2 Vulnerability Overview 3.2.1 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 The deprecated compatibility function svcunix_create in the sunrpc module of the GNU C Library (aka glibc) through 2.34 copies its path argument on the stack without validating its length, which may result in a buffer overflow, potentially resulting in a denial of service or (if an application is not built with a stack protector enabled) arbitrary code execution. CVE-2022-23218 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.2 BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120 The deprecated compatibility function clnt_create in the sunrpc module of the GNU C Library (aka glibc) through 2.34 copies its hostname argument on the stack without validating its length, which may result in a buffer overflow, potentially resulting in a denial of service or (if an application is not built with a stack protector enabled) arbitrary code execution. CVE-2022-23219 has been assigned to this vulnerability. A CVSS v3 base score of 9.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). 3.2.3 NULL POINTER DEREFERENCE CWE-476 handle_ipDefaultTTL in agent/mibgroup/ip-mib/ip_scalars.c in Net-SNMP 5.8 through 5.9.3 has a NULL Pointer Exception bug that can be used by a remote attacker (who has write access) to cause the instance to crash via a crafted UDP packet, resulting in denial of service. CVE-2022-44792 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H). 3.2.4 NULL POINTER DEREFERENCE CWE-476 handle_ipv6IpForwarding in agent/mibgroup/ip-mib/ip_scalars.c in Net-SNMP 5.4.3 through 5.9.3 has a NULL pointer exception bug that can be used by a remote attacker to cause the instance to crash via a crafted UDP packet, resulting in denial of service. CVE-2022-44793 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H). 3.2.5 IMPROPER AUTHENTICATION CWE-287 The AES-SIV cipher implementation contains a bug that causes it to ignore empty associated data entries which are unauthenticated as a consequence. Impact summary: Applications that use the AES-SIV algorithm and want to authenticate empty data entries as associated data can be misled by removing adding or reordering such empty entries as these are ignored by the OpenSSL implementation. We are currently unaware of any such applications. The AES-SIV algorithm allows for authentication of multiple associated data entries along with the encryption. To authenticate empty data the application has to call EVP_EncryptUpdate() (or EVP_CipherUpdate()) with NULL pointer as the output buffer and 0 as the input buffer length. The AES-SIV implementation in OpenSSL just returns success for such a call instead of performing the associated data authentication operation. The empty data thus will not be authenticated. As this issue does not affect non-empty associated data authentication and we expect it to be rare for an application to use empty associated data entries this is qualified as Low severity issue. CVE-2023-2975 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N). 3.2.6 INEFFICIENT REGULAR EXPRESSION COMPLEXITY CWE-1333 Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. One of those checks confirms that the modulus ('p' parameter) is not too large. Trying to use a very large modulus is slow and OpenSSL will not normally use a modulus which is over 10,000 bits in length. However, the DH_check() function checks numerous aspects of the key or parameters that have been supplied. Some of those checks use the supplied modulus value even if it has already been found to be too large. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulernable to a Denial-of-Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the '-check' option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue. CVE-2023-3446 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). 3.2.7 EXCESSIVE ITERATION CWE-834 Checking excessively long DH keys or parameters may be very slow. Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service. The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p. An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial-of-Service attack. The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue. CVE-2023-3817 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). 3.2.8 OUT-OF-BOUNDS WRITE CWE-787 An issue was discovered in fl_set_geneve_opt in net/sched/cls_flower.c in the Linux kernel before 6.3.7. It allows an out-of-bounds write in the flower classifier code via TCA_FLOWER_KEY_ENC_OPTS_GENEVE packets. This may result in denial of service or privilege escalation. CVE-2023-35788 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; the CVSS vector string is ( CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). 3.3 BACKGROUND CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing COUNTRIES/AREAS DEPLOYED: Worldwide COMPANY HEADQUARTERS LOCATION: Germany 3.4 RESEARCHER Siemens reported these vulnerabilities to CISA. 4. MITIGATIONS Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk: SIMATIC MV500 family: Update to V3.3.5 or later version As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals. Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage. For more information see the associated Siemens security advisory SSA-099606 in HTML and CSAF. CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities, such as: Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs). Recognize VPNs may have vulnerabilities, should be updated to the most recent version available, and are only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. 5. UPDATE HISTORY November 16, 2023: Initial Publication