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CVE-2024-35849 Siemens CVE debrief

This CVE addresses an information leak vulnerability in the Linux kernel's Btrfs filesystem, specifically within the `btrfs_ioctl_logical_to_ino()` function. The vulnerability was resolved in the upstream Linux kernel. Siemens has identified this as affecting the GNU/Linux subsystem of their SIMATIC S7-1500 TM MFP industrial control product. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H) indicates a local attack vector requiring low privileges, with high impact to confidentiality and availability but no integrity impact. As of the source advisory publication, no fix was available from Siemens; mitigations focus on restricting access to the interactive shell and ensuring only trusted applications are executed.

Vendor
Siemens
Product
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS
HIGH 7.1
CISA KEV
Not listed in stored evidence
Original CVE published
2024-04-09
Original CVE updated
2026-05-14
Advisory published
2024-04-09
Advisory updated
2026-05-14

Who should care

Organizations operating Siemens SIMATIC S7-1500 TM MFP industrial control systems with the GNU/Linux subsystem enabled; OT security teams managing embedded Linux environments in industrial settings; asset owners requiring defense-in-depth strategies for unpatched ICS vulnerabilities

Technical summary

The vulnerability exists in the `btrfs_ioctl_logical_to_ino()` function of the Linux kernel's Btrfs filesystem implementation. This ioctl handler could leak sensitive information under certain conditions. The issue was resolved upstream in the Linux kernel. The Siemens SIMATIC S7-1500 TM MFP incorporates a GNU/Linux subsystem that is affected by this kernel-level vulnerability. The local attack vector requires an attacker to have low-privilege access to the target system. Successful exploitation could result in high confidentiality impact (information disclosure) and high availability impact, though integrity is not affected. No integrity impact suggests the vulnerability does not allow data modification or code execution directly, but information leakage and potential denial-of-service conditions are possible.

Defensive priority

high

Recommended defensive actions

  • Restrict interactive shell access to the GNU/Linux subsystem to trusted personnel only
  • Ensure only applications from trusted sources are built and executed on affected systems
  • Monitor for Siemens security advisories (SSA-265688) for patch availability
  • Apply defense-in-depth strategies for industrial control systems per CISA guidance
  • Review and implement ICS-CERT recommended practices for securing embedded Linux subsystems

Evidence notes

CVE published 2024-04-09 per official record. Source advisory ICSA-24-102-01 published same date. Modified 2026-05-14. CVSS 7.1 (HIGH) per source. Affects Siemens SIMATIC S7-1500 TM MFP GNU/Linux subsystem. No fix available per source remediation data; mitigations provided.

Official resources

2024-04-09