PatchSiren cyber security CVE debrief

CVE-2024-42345 Siemens CVE debrief

A session management vulnerability in Siemens SINEMA Remote Connect Server allows remote attackers to bypass multi-factor authentication (MFA) during user session establishment. The affected application fails to properly handle session establishment and invalidation, enabling MFA circumvention. Siemens has released a vendor fix in version V3.2 SP2 or later. The vulnerability carries a CVSS 3.1 score of 4.3 (Medium severity) with network attack vector, low attack complexity, and low privileges required. Published September 10, 2024, this issue affects industrial remote connectivity infrastructure and should be prioritized for patching in environments where SINEMA Remote Connect Server manages secure remote access to OT/ICS networks.

Vendor: Siemens
Product: SINEMA Remote Connect Server
CVSS: MEDIUM 4.3
CISA KEV: Not listed in stored evidence
Original CVE published: 2024-09-10
Original CVE updated: 2024-09-10
Advisory published: 2024-09-10
Advisory updated: 2024-09-10

Who should care

Organizations operating Siemens SINEMA Remote Connect Server for remote access to industrial networks, particularly those in critical infrastructure sectors relying on MFA for secure remote connectivity. Security teams responsible for OT/ICS infrastructure, network administrators managing remote access solutions, and compliance officers ensuring authentication controls meet security requirements.

Technical summary

The vulnerability exists in the session establishment and invalidation logic of SINEMA Remote Connect Server. Improper handling of user sessions allows a remote attacker with low privileges to circumvent multi-factor authentication requirements when establishing a user session. The flaw does not require user interaction and can be exploited over the network with low attack complexity. The confidentiality impact is none, integrity impact is low, and availability impact is none per the CVSS vector. Siemens has addressed this in V3.2 SP2 through improved session management controls.

Defensive priority

medium

Recommended defensive actions

Apply vendor fix: Update SINEMA Remote Connect Server to V3.2 SP2 or later version
Review session management configurations for proper invalidation behavior
Implement network segmentation to limit exposure of SINEMA Remote Connect Server management interfaces
Monitor for anomalous authentication patterns that may indicate MFA bypass attempts
Apply defense-in-depth controls per CISA ICS recommended practices for industrial control systems

Evidence notes

Vulnerability description and remediation guidance sourced from CISA ICS advisory ICSA-24-256-01 and Siemens security advisory SSA-869574. CVSS vector confirms network-accessible attack with low complexity. Vendor fix explicitly identified as V3.2 SP2 or later.

Official resources

2024-09-10