Improper input validation in Modicon M241/M251 logic controllers firmware prior to…
Priority LOW 35CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
Improper Input Validation vulnerability exists in Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 that could cause denial of service when specific crafted requests are sent to the controller over HTTP.
Why it matters now
EPSS 0.00978 62nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 | Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 | — | No fix listed | CNA |
- Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 Vendor— Affected Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:schneider-electric:modicon_m241_firmware:*:*:*:*:*:*:*:* | before 5.1.9.1 | Vulnerable | Schneider Electric |
| cpe:2.3:h:schneider-electric:modicon_m241:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Schneider Electric |
| cpe:2.3:o:schneider-electric:modicon_m251_firmware:*:*:*:*:*:*:*:* | before 5.1.9.1 | Vulnerable | Schneider Electric |
| cpe:2.3:h:schneider-electric:modicon_m251:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Schneider Electric |
- cpe:2.3:o:schneider-electric:modicon_m241_firmware:*:*:*:*:*:*:*:* Versions before 5.1.9.1 Vulnerable ·Schneider Electric
- cpe:2.3:h:schneider-electric:modicon_m241:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Schneider Electric
- cpe:2.3:o:schneider-electric:modicon_m251_firmware:*:*:*:*:*:*:*:* Versions before 5.1.9.1 Vulnerable ·Schneider Electric
- cpe:2.3:h:schneider-electric:modicon_m251:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Schneider Electric
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-22699
- 2026-10-03 Alias added: GHSA-6vx6-7ghj-3776
References
More Schneider Electric Modicon M241 Firmware vulnerabilities
- TI-2017-03936 A Use of Insufficiently Random Values issue was discovered in Schneider Electric Modicon… CVSS 3.1CRITICAL 9.1
- TI-2017-03938 Insufficiently protected credentials in Schneider Electric Modicon PLCs CVSS 3.1CRITICAL 9.8
- TI-2019-04853 Missing authentication in Modicon and PacDrive Controller, All versions of: Modicon M100… CVSS 3.1HIGH 8.2
- TI-2020-06010 Insufficient verification of data authenticity in EcoStruxure Machine Expert SoMachine… CVSS 3.1CRITICAL 9.8
- TI-2020-06011 Cleartext transmission of sensitive information in EcoStruxure Machine Expert SoMachine… CVSS 3.1HIGH 7.5
- TI-2017-03940 Schneider Electric Modicon PLCs Predictable Value Range from Previous Values CVSS 3.1MEDIUM 6.5
Sources
- CVE-2021-22699 · CVE Program
- CVE-2021-22699 · NVD
- FIRST EPSS
- GHSA-6vx6-7ghj-3776 · GitHub Advisory Database · CC BY 4.0
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