Authentication bypass by capture-replay in Schneider Electric Modicon M221, all…
Priority MEDIUM 53CWE-294Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-294.
Summary
An Information Management Error vulnerability exists in Schneider Electric's Modicon M221 product (all references, all versions prior to firmware V1.6.2.0). The vulnerability allows unauthorized users to replay authentication sequences. If an attacker exploits this vulnerability and connects to a Modicon M221, the attacker can upload the original program from the PLC.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02384 84th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Schneider Electric | Modicon M221, all references, all versions prior to firmware V1.6.2.0 | Modicon M221, all references, all versions prior to firmware V1.6.2.0 | — | No fix listed | CNA |
- Modicon M221, all references, all versions prior to firmware V1.6.2.0 VendorSchneider Electric Affected Modicon M221, all references, all versions prior to firmware V1.6.2.0 Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:schneider-electric:modicon_m221_firmware:*:*:*:*:*:*:*:* | before 1.6.2.0 | Vulnerable | Schneider Electric |
| cpe:2.3:h:schneider-electric:modicon_m221:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Schneider Electric |
- cpe:2.3:o:schneider-electric:modicon_m221_firmware:*:*:*:*:*:*:*:* Versions before 1.6.2.0 Vulnerable ·Schneider Electric
- cpe:2.3:h:schneider-electric:modicon_m221:-:*:*:*:*:*:*:* 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-2018-7790
- 2026-10-03 Alias added: GHSA-xvmg-mf7x-g2hx
References
More Schneider Electric Modicon M221 Firmware vulnerabilities
- TI-2018-05633 Improper access control in Schneider Electric Modicon M221, all references, all versions… CVSS 3.1CRITICAL 9.8
- TI-2020-06012 Injection in SoMachine Basic EcoStruxure Machine Expert – Basic Modicon M100 Logic… CVSS 3.1CRITICAL 9.8
- TI-2020-17144 A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon… CVSS 3.1CRITICAL 9.8
- TI-2019-08172 Uncontrolled resource consumption in ABB 1SAP120600R0071 PM554-TP-ETH CVSS 3.1HIGH 7.5
- TI-2019-04853 Missing authentication in Modicon and PacDrive Controller, All versions of: Modicon M100… CVSS 3.1HIGH 8.2
- TI-2018-05659 Uncontrolled resource consumption in SoMachine Basic and Modicon M221, SoMachine Basic… CVSS 3.1HIGH 7.5
Sources
- CVE-2018-7790 · CVE Program
- CVE-2018-7790 · NVD
- FIRST EPSS
- GHSA-xvmg-mf7x-g2hx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences