Modicon M340 CPUs: Improper Privilege Management
CVE-2022-0222 is a high-severity improper privilege management vulnerability in Modicon M340 CPUs from Schneider Electric, 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. The record lists version V3.40 as the first without the flaw, so updating Modicon M340 CPUs to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Modicon M340 CPUs to V3.40 or a later version.
- Update Modicon M340 X80 Ethernet Communication modules: BMXNOE0100 (H) BMXNOE0110 (H) BMXNOR0200H RTU to v1.7 IR24 or a later version.
- Update Modicon M340 Bmxp341000 Firmware to 3.50 or a later version.
- Read the advisory on se.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
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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (se.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A CWE-269: Improper Privilege Management vulnerability exists that could cause a denial of service of the Ethernet communication of the controller when sending a specific request over SNMP. Affected products: Modicon M340 CPUs(BMXP34* versions prior to V3.40), Modicon M340 X80 Ethernet Communication modules:BMXNOE0100 (H), BMXNOE0110 (H), BMXNOR0200H RTU(BMXNOE* all versions)(BMXNOR* versions prior to v1.7 IR24)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Privilege Management
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Improper Privilege Management vulnerabilities (CWE-269)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Recent Improper Privilege Management vulnerabilities
- 8.8 High severity
- 9.9 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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