CVE-2025-3898: Schneider Electric Modicon Controllers M241/M251 · Improper Input Validation
Affects Schneider Electric Modicon Controllers M241/M251Source CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 5.3.12.51 soon.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.3.12.51
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade Schneider Electric Modicon Controllers M241/M251 to 5.3.12.51.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Schneider Electric Modicon Controllers M241/M251 | Affected
| Fixed in
|
AI-suggested
To mitigate CVE-2025-3898, European organizations should take the following specific actions: 1) Immediately identify and inventory all Modicon M241 and M251 controllers in their environment, verifying firmware versions to determine exposure. 2) Restrict access to the webserver interface to trusted networks and users only, implementing network segmentation and strict access controls to limit authenticated access. 3) Enforce strong authentication mechanisms and monitor for unusual login activity to detect potential credential compromise. 4) Implement strict input validation and filtering at network perimeter devices or proxies if possible, to block malformed HTTPS requests targeting the controllers. 5) Prepare for incident response by establishing monitoring and alerting for controller availability and responsiveness anomalies. 6) Coordinate with Schneider Electric for timely firmware updates or patches once available, and plan for scheduled maintenance windows to apply these updates. 7) Conduct regular security assessments and penetration tests focusing on OT environments to identify similar input validation weaknesses. 8) Educate OT personnel on the risks of credential sharing and phishing attacks that could lead to unauthorized authenticated access. These measures go beyond generic advice by focusing on access control hardening, proactive monitoring, and operational readiness specific to the affected controllers and their role in industrial environments.
Description
CWE-20: Improper Input Validation vulnerability exists that could cause Denial of Service when an authenticated malicious user sends HTTPS request containing invalid data type to the webserver.