Siemens License Server Vulnerable to Privilege Escalation and Path Traversal
Multiple vulnerabilities in Siemens License Server versions prior to V5.1 and V5.3 could allow attackers to escalate privileges and access sensitive files.
Siemens has issued a security advisory detailing multiple vulnerabilities affecting its Siemens License Server (SLS) software. Versions prior to V5.1 and V5.3 are susceptible to flaws that could permit attackers to gain elevated privileges and read arbitrary files on the system, potentially leading to a full system compromise.
The first vulnerability, identified as CVE-2026-69108, is a local privilege escalation flaw stemming from an insecure sudoers policy. This vulnerability allows an attacker with local access to execute arbitrary commands with root privileges, enabling them to plant malicious files and take complete control of the affected system. The Common Vulnerability Scoring System (CVSS) v3.1 base score for this issue is 6 (MEDIUM), with a vector string of CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N, indicating a moderate risk for local attackers with high privileges.
Compounding the risk, CVE-2026-69109 is a path traversal vulnerability. This flaw arises from a lack of proper sanitization of user input, which could allow a remote attacker to access arbitrary files on the application's server. This vulnerability carries a higher CVSS v3.1 base score of 7.5 (HIGH), with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N, signifying a significant risk for unauthenticated remote attackers.
Siemens has addressed these vulnerabilities by releasing updated versions of the Siemens License Server. Users are strongly advised to update to version V5.1 or later for the first vulnerability and V5.3 or later for the second to mitigate these risks. The company provides links to download the latest versions and detailed information on its support portal.
These vulnerabilities were reported to CISA by Siemens ProductCERT. CISA, in turn, is urging organizations to implement defensive measures to minimize the exploitation risk. These recommendations include minimizing network exposure of control system devices, ensuring they are not accessible from the internet, and isolating them behind firewalls.
For remote access, CISA recommends using secure methods like Virtual Private Networks (VPNs), while also emphasizing the importance of keeping VPN software updated. Organizations are encouraged to perform thorough impact analyses and risk assessments before deploying any security measures.
The Siemens License Server is used in various industrial environments, and its compromise could have significant implications for operational technology (OT) systems. The combination of privilege escalation and arbitrary file access makes these vulnerabilities particularly dangerous, potentially allowing attackers to disrupt operations, steal sensitive data, or use the compromised system as a pivot point for further network intrusion.
Siemens has provided operational guidelines for industrial security and encourages users to consult their product manuals for further security best practices. The company also maintains a dedicated portal for information on security vulnerabilities in its products.