CVE-2025-40795
Published: 09 September 2025
Summary
CVE-2025-40795 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Siemens Simatic Pcs Neo. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 40.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Deeper analysis
CVE-2025-40795 is a stack-based buffer overflow vulnerability (CWE-121) affecting the integrated User Management Component (UMC) in SIMATIC PCS neo versions V4.1, V5.0, and V6.0 (all versions), as well as standalone UMC versions prior to V2.15.1.3. Published on September 9, 2025, the flaw resides in the UMC component common to these Siemens industrial automation products, earning a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.
An unauthenticated remote attacker can exploit this vulnerability over the network with low complexity and no user interaction required. Successful exploitation could enable arbitrary code execution on the affected system or trigger a denial-of-service condition, potentially disrupting industrial control operations.
Siemens has published security advisory SSA-722410, available at https://cert-portal.siemens.com/productcert/html/ssa-722410.html, which provides details on mitigation, including updating to UMC V2.15.1.3 or later where applicable. Security practitioners should consult the advisory for version-specific patching instructions and workarounds for unpatchable systems.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-27240
Vulnerability details
A vulnerability has been identified in SIMATIC PCS neo V4.1 (All versions), SIMATIC PCS neo V5.0 (All versions), SIMATIC PCS neo V6.0 (All versions < V6.0 SP1 Update 1), User Management Component (UMC) (All versions < V2.15.1.3). Affected products contain…
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a stack-based buffer overflow vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to execute arbitrary code or to cause a denial of service condition.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated stack buffer overflow enabling arbitrary code execution on a network-accessible industrial management component directly maps to exploitation of public-facing applications for initial access.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Requires timely remediation of the identified stack-based buffer overflow vulnerability through patching to UMC V2.15.1.3 or later, directly eliminating the flaw.
Implements memory protection mechanisms such as stack canaries, ASLR, and non-executable memory stacks that directly thwart exploitation of stack-based buffer overflows.
Enforces validation of inputs to the UMC component to prevent buffer overflows from malformed or oversized data processed by unauthenticated remote attackers.