PatchSiren cyber security CVE debrief

CVE-2024-39867 Siemens CVE debrief

A high-severity authentication bypass vulnerability in Siemens SINEMA Remote Connect Server allows unauthenticated attackers to access and modify device configurations for which they lack authorization. The flaw stems from improper authentication validation during specific web interface actions. Published July 9, 2024, this vulnerability carries a CVSS 3.1 score of 7.6 (HIGH severity). Siemens has released a vendor fix in version V3.2 SP1 or later. Organizations should prioritize patching, especially for internet-exposed management interfaces, and implement network segmentation to limit attack surface.

Vendor: Siemens
Product: SINEMA Remote Connect Server
CVSS: HIGH 7.6
CISA KEV: Not listed in stored evidence
Original CVE published: 2024-07-09
Original CVE updated: 2024-07-09
Advisory published: 2024-07-09
Advisory updated: 2024-07-09

Who should care

Organizations operating Siemens SINEMA Remote Connect Server for remote industrial network management, particularly those with web interfaces exposed to broader network segments. Critical infrastructure operators, manufacturing facilities, and utilities using this platform for secure remote access to OT environments should prioritize assessment and patching.

Technical summary

The vulnerability exists in the web interface of SINEMA Remote Connect Server where certain actions fail to properly validate authentication state. An unauthenticated attacker can exploit this flaw to access device configuration information and perform unauthorized edits on devices beyond their privilege scope. The attack requires network access to the web interface with low complexity and no user interaction. The CVSS vector indicates high availability impact alongside confidentiality and integrity impacts, suggesting potential for service disruption through configuration tampering.

Defensive priority

high

Recommended defensive actions

Apply vendor patch: Update SINEMA Remote Connect Server to V3.2 SP1 or later version as specified in Siemens security advisory
Restrict network access: Limit web interface exposure to trusted administrative networks only; avoid internet-facing deployments where possible
Review access logs: Examine web interface access logs for unauthorized configuration changes or anomalous access patterns prior to patching
Implement defense in depth: Apply CISA ICS recommended practices for network segmentation and industrial control system security
Verify configuration integrity: After patching, audit device configurations to ensure no unauthorized modifications were made

Evidence notes

Authentication bypass confirmed in CISA ICS advisory ICSA-24-193-01 and Siemens security advisory SSA-381581. CVSS vector AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H indicates network attack vector with low attack complexity, low privileges required, and high availability impact. Remediation guidance specifies update to V3.2 SP1 or later.

Official resources

2024-07-09