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 6.6
- ATTENTION: Exploitable remotely
- Vendor: Siemens
- Equipment: SICAM A8000
- Vulnerability: Use of Uninitialized Resource
2. RISK EVALUATION
Successful exploitation of this vulnerability could allow an authenticated remote attacker to inject commands that are executed on the device with root privileges during device startup.
3. TECHNICAL DETAILS
3.1 AFFECTED PRODUCTS
The following Siemens products, are affected:
- CP-8031 MASTER MODULE (6MF2803-1AA00): All versions prior to CPCI85 V05.20
- CP-8050 MASTER MODULE (6MF2805-0AA00): All versions prior to CPCI85 V05.20
3.2 Vulnerability Overview
3.2.1 USE OF UNINITIALIZED RESOURCE CWE-908
The network configuration service of affected devices contains a flaw in the conversion of ipv4 addresses that could lead to an uninitialized variable being used in succeeding validation steps. By uploading specially crafted network configuration, an authenticated remote attacker could be able to inject commands that are executed on the device with root privileges during device startup.
CVE-2023-42797 has been assigned to this vulnerability. A CVSS v3 base score of 6.6 has been assigned; the CVSS vector string is (CVSS:3.1/AV:N/AC:H/PR:H/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 this vulnerability to CISA.
4. MITIGATIONS
Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:
CP-8031 MASTER MODULE (6MF2803-1AA00):
- Review the list of users that are allowed to modify the network configuration and apply strong passwords.
- Update to CPCI85 V05.20 or later version
CP-8050 MASTER MODULE (6MF2805-0AA00):
- Review the list of users that are allowed to modify the network configuration and apply strong passwords.
- Update to CPCI85 V05.20 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-583634 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
- January 11, 2024: Initial Publication
