Siemens SCALANCE X Switch Devices

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).

1. EXECUTIVE SUMMARY

• CVSS v3 9.6
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Siemens
• Equipment: SCALANCE X Switch Devices
• Vulnerabilities: Use of Insufficiently Random Values, Classic Buffer Overflow

2. RISK EVALUATION

Successful exploitation of these vulnerabilities may allow an attacker to reboot, cause denial-of-service conditions, or impact the system by other means through a buffer overflow.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of SCALANCE X Switch Devices, industrial ethernet switches, are affected:

• SCALANCE X200-4P IRT (6GK5200-4AH00-2BA3): All versions
• SCALANCE X200-4P IRT (6GK5200-4AH10-2BA3): All versions
• SCALANCE X201-3P IRT (6GK5201-3BH00-2BA3): All versions
• SCALANCE X201-3P IRT (6GK5201-3BH10-2BA3): All versions
• SCALANCE X201-3P IRT PRO (6GK5201-3BH00-2BD2): All versions
• SCALANCE X201-3P IRT PRO (6GK5201-3JR10-2BA6): All versions
• SCALANCE X202-2IRT (6GK5202-2BB00-2BA3): All versions
• SCALANCE X202-2IRT (6GK5202-2BB10-2BA3): All versions
• SCALANCE X202-2P IRT (6GK5202-2BH00-2BA3): All versions
• SCALANCE X202-2P IRT (6GK5202-2BH10-2BA3): All versions
• SCALANCE X202-2P IRT PRO (6GK5202-2JR00-2BA6): All versions
• SCALANCE X202-2P IRT PRO (6GK5202-2JR10-2BA6): All versions
• SCALANCE X204-2 (6GK5204-2BB10-2AA3): All versions prior to v5.2.6
• SCALANCE X204-2FM (6GK5204-2BB11-2AA3): All versions prior to v5.2.6
• SCALANCE X204-2LD (6GK5204-2BC10-2AA3): All versions prior to v5.2.6
• SCALANCE X204-2LD TS (6GK5204-2BC10-2CA2): All versions prior to v5.2.6
• SCALANCE X204-2TS (6GK5204-2BB10-2CA2): All versions prior to v5.2.6
• SCALANCE X204IRT (6GK5204-0BA00-2BA3): All versions
• SCALANCE X204IRT (6GK5204-0BA10-2BA3): All versions
• SCALANCE X204IRT PRO (6GK5204-0JA00-2BA6): All versions
• SCALANCE X204IRT PRO (6GK5204-0JA10-2BA6): All versions
• SCALANCE X206-1 (6GK5206-1BB10-2AA3): All versions prior to v5.2.6
• SCALANCE X206-1LD (6GK5206-1BC10-2AA3): All versions prior to v5.2.6
• SCALANCE X208 (6GK5208-0BA10-2AA3): All versions prior to v5.2.6
• SCALANCE X208PRO (6GK5208-0HA10-2AA6): All versions prior to v5.2.6
• SCALANCE X212-2 (6GK5212-2BB00-2AA3): All versions prior to v5.2.6
• SCALANCE X212-2LD (6GK5212-2BC00-2AA3): All versions prior to v5.2.6
• SCALANCE X216 (6GK5216-0BA00-2AA3): All versions prior to v5.2.6
• SCALANCE X224 (6GK5224-0BA00-2AA3): All versions prior to v5.2.6
• SCALANCE XF201-3P IRT (6GK5201-3JR00-2BA6): All versions
• SCALANCE XF202-2P IRT (6GK5202-2BH00-2BD2): All versions
• SCALANCE XF204 (6GK5204-0BA00-2AF2): All versions prior to v5.2.6
• SCALANCE XF204-2 (6GK5204-2BC00-2AF2): All versions prior to v5.2.6
• SCALANCE XF204-2BA IRT (6GK5204-2AA00-2BD2): All versions
• SCALANCE XF204IRT (6GK5204-0BA00-2BF2): All versions
• SCALANCE XF204IRT (6GK5204-0BA10-2BF2): All versions
• SCALANCE XF206-1 (6GK5206-1BC00-2AF2): All versions prior to v5.2.6
• SCALANCE XF208 (6GK5208-0BA00-2AF2): All versions prior to v5.2.6

3.2 VULNERABILITY OVERVIEW

3.2.1    USE OF INSUFFICIENTLY RANDOM VALUES CWE-330

The webserver of affected devices calculates session IDs and nonces in an insecure manner. This could allow an unauthenticated remote attacker to brute force session IDs and hijack existing sessions.

CVE-2022-26647 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been assigned; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

3.2.2    BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120

Affected devices do not properly validate the GET parameter XNo of incoming HTTP requests. This could allow an unauthenticated remote attacker to crash affected devices.

CVE-2022-26648 has been assigned to this vulnerability. A CVSS v3 base score of 8.2 has been assigned; the CVSS vector string is (AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H)

3.2.3    BUFFER COPY WITHOUT CHECKING SIZE OF INPUT ('CLASSIC BUFFER OVERFLOW') CWE-120

Affected devices do not properly validate the URI of incoming HTTP GET requests. This could allow an unauthenticated remote attacker to crash affected devices.

CVE-2022-26649 has been assigned to this vulnerability. A CVSS v3 base score of 9.6 has been assigned; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).

3.3 BACKGROUND

•    CRITICAL INFRASTRUCTURE SECTORS: Multiple Sectors

•    COUNTRIES/AREAS DEPLOYED: Worldwide

•    COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Siemens reported these vulnerabilities to CISA.

4. MITIGATIONS

Siemens recommends updating to the latest version of its software if available:

• The products listed are only affected up to v5.2.6. Update to v5.2.6 or later

Siemens has identified the following specific workarounds and mitigations that customers can implement to reduce exploitation risk:

• Restrict access to the affected systems, especially on port 80/TCP and port 443/TCP, to trusted IP addresses
• Deactivate the webserver if not required and if deactivation is supported by the product

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 Siemens Security Advisory SSA-310038.

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 at 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.

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.

No known public exploits specifically target these vulnerabilities.