CVE-2023-21255 Siemens CVE debrief

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).

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.