Vulnerability · Published Dec 9, 2025 · Assigned by siemens
CVE-2025-40939
Medium 4.6
In plain English
A medium-severity improper access control in SIMATIC CN 4100 from Siemens. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).
Severity (CVSS 3.1)4.6Medium
Exploit odds (30 days)0.2%top 88.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device contains a USB port which allows unauthenticated connections. This could allow an attacker with physical access to the device to trigger reboot that could cause denial of service condition.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Siemens | SIMATIC CN 4100 | 0 – before V4.0.1 |
Weakness: CWE-284 · Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H