CVE-2024-43830 Siemens CVE debrief

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP industrial control systems with the GNU/Linux subsystem enabled, particularly those allowing interactive shell access or running custom applications that may interact with LED triggers. System administrators responsible for securing OT/ICS environments and maintaining defense-in-depth strategies should prioritize access controls until patches become available.

Technical summary

The vulnerability is a use-after-free (CWE-416) in the Linux kernel's LED trigger subsystem. The root cause is incorrect cleanup ordering: device_remove_groups() was called after deactivate(), allowing concurrent sysfs attribute access to freed trigger-data. The fix reorders operations to unregister sysfs attributes before deactivation, matching the reverse order of activation (activate() before device_add_groups()). This affects systems where LED triggers with custom sysfs attributes are used, including the GNU/Linux subsystem on Siemens SIMATIC S7-1500 TM MFP industrial controllers.

Defensive priority

medium

Recommended defensive actions

• Limit access to the interactive shell of the additional GNU/Linux subsystem to trusted personnel only
• Only build and run applications from trusted sources
• Monitor for updates from Siemens regarding patch availability for SSA-265688

Evidence notes

The vulnerability description is sourced from CISA CSAF advisory ICSA-24-102-01, which references Siemens security advisory SSA-265688. The affected product is explicitly identified as SIMATIC S7-1500 TM MFP - GNU/Linux subsystem. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H) indicates local attack vector with low attack complexity, requiring low privileges, with high availability impact. The advisory notes no fix is currently available as of the source publication date.

Official resources