SIMATIC PCS neo V4.1: Out-of-bounds Read
CVE-2025-40797 is a high-severity out-of-bounds read vulnerability in SIMATIC PCS neo V4.1 from Siemens, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SIMATIC PCS neo V4.1 versions: all versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update SIMATIC PCS neo V6.0 to V6.0 SP1 Update 1 or a later version.
- Update User Management Component (UMC) to V2.15.1.3 or a later version.
- Update User Management Component to 2.15.1.3 or a later version.
- Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Siemens | SIMATIC PCS neo V4.1 | all versions | Not stated |
| Siemens | SIMATIC PCS neo V5.0 | all versions | Not stated |
| Siemens | SIMATIC PCS neo V6.0 | before V6.0 SP1 Update 1 | V6.0 SP1 Update 1 |
| Siemens | User Management Component (UMC) | before V2.15.1.3 | V2.15.1.3 |
| Siemens | Simatic Pcs Neo | 4.1; 5.0 | Not stated |
| Siemens | User Management Component | before 2.15.1.3 | 2.15.1.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (siemens.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (siemens.com) |
| CVSS 3.1 | 7.5 | High | CNA (siemens.com) |
Official description
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 a out-of-bounds read vulnerability in the integrated UMC component. This could allow an unauthenticated remote attacker to cause a denial of service condition.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in SIMATIC PCS neo V4.1
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.2 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Out-of-bounds Read vulnerabilities
- 9.1 Critical severity
- 7.8 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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