PatchSiren cyber security CVE debrief

CVE-2024-35902 Siemens CVE debrief

CVE-2024-35902 is a medium-severity vulnerability (CVSS 5.5) in the Linux kernel's Reliable Datagram Sockets (RDS) subsystem, specifically affecting the `__rds_rdma_map` function where a null pointer dereference can occur. The parameter `cp` may be null, and calling `cp->cp_conn` without validation leads to a potential denial-of-service condition. This vulnerability was published on April 9, 2024, and affects Siemens SIMATIC S7-1500 TM MFP industrial control systems through their GNU/Linux subsystem. CISA and Siemens have issued coordinated advisories tracking this issue. No patch is currently available from the vendor.

Vendor: Siemens
Product: SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
CVSS: MEDIUM 5.5
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

Industrial control system operators, OT security teams, Siemens SIMATIC S7-1500 TM MFP administrators, critical infrastructure security personnel, and organizations running Linux-based embedded systems in operational technology environments

Technical summary

The vulnerability exists in `net/rds` where the `cp` parameter in `__rds_rdma_map` may be null. When `cp->cp_conn` is dereferenced without null checking, a kernel panic or denial-of-service condition can occur. This is a local vulnerability requiring low privileges to exploit, with high availability impact but no confidentiality or integrity impact.

Defensive priority

medium

Recommended defensive actions

Restrict interactive shell access to the GNU/Linux subsystem on affected Siemens SIMATIC S7-1500 TM MFP devices to trusted personnel only
Only build and run applications from trusted sources on affected systems
Monitor for vendor security updates from Siemens for patch availability
Apply defense-in-depth strategies for industrial control systems per CISA guidance
Review network segmentation to limit exposure of affected industrial control devices

Evidence notes

The vulnerability description is sourced directly from CISA CSAF data and Siemens security advisories. The CVSS vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H indicates a local attack vector with low attack complexity, requiring low privileges, resulting in high availability impact with no confidentiality or integrity impact.

Official resources

This vulnerability was disclosed through coordinated disclosure between the Linux kernel security team, CISA, and Siemens. The issue was published in CISA advisory ICSA-24-102-01 on April 9, 2024, with subsequent updates through September 9