PatchSiren cyber security CVE debrief

CVE-2023-21255 Siemens CVE debrief

A use-after-free vulnerability in the Android binder driver (binder.c) affects Siemens TIM 1531 IRC industrial communication modules. The flaw enables local privilege escalation without requiring user interaction or additional execution privileges. Siemens has released firmware version 2.4.8 to address this vulnerability.

Vendor: Siemens
Product: SIPLUS TIM 1531 IRC (6AG1543-1MX00-7XE0)
CVSS: HIGH 7.8
CISA KEV: Not listed in stored evidence
Original CVE published: 2024-02-13
Original CVE updated: 2024-02-13
Advisory published: 2024-02-13
Advisory updated: 2024-02-13

Who should care

Organizations operating Siemens TIM 1531 IRC modules in industrial environments, particularly those in critical infrastructure sectors. OT security teams, ICS asset owners, and network administrators responsible for industrial communication systems should prioritize patching. Organizations with remote or distributed industrial sites using these modules for telecontrol and WAN communication are at elevated risk if local access can be obtained.

Technical summary

CVE-2023-21255 is a use-after-free vulnerability in multiple functions of binder.c, the Android inter-process communication driver. The flaw can result in memory corruption and local privilege escalation without requiring user interaction or elevated privileges. While the vulnerability originates in Android's binder subsystem, it affects Siemens TIM 1531 IRC industrial communication modules that incorporate the vulnerable component. The CVSS v3.1 score of 7.8 reflects high impacts to confidentiality, integrity, and availability with a local attack vector. Siemens has addressed this in firmware version 2.4.8.

Defensive priority

HIGH

Recommended defensive actions

Apply Siemens firmware update to version 2.4.8 or later for affected TIM 1531 IRC devices
Review and implement CISA ICS recommended practices for defense-in-depth strategies
Monitor Siemens ProductCERT portal for additional security advisories related to TIM 1531 IRC
Assess network segmentation to limit exposure of affected industrial communication modules
Verify firmware version on deployed TIM 1531 IRC devices and prioritize patching on internet-facing or critical infrastructure systems

Evidence notes

The vulnerability description indicates memory corruption via use-after-free in binder.c functions, with CVSS 7.8 (HIGH). CISA published advisory ICSA-24-165-06 on 2024-06-11, with a revision on 2024-07-09. Siemens SSA-337522 provides the vendor fix. The affected products are SIPLUS TIM 1531 IRC (6AG1543-1MX00-7XE0) and TIM 1531 IRC (6GK7543-1MX00-0XE0).

Official resources

2024-06-11