Modicon M340 CPU (part numbers BMXP34*): Improper Enforcement of Message Integrity During Transmission in a Communication Channel
CVE-2024-8933 is a high-severity improper enforcement of message integrity during transmission in a communication channel vulnerability in Modicon M340 CPU (part numbers BMXP34*) 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, but only if a user takes part, for example by opening a link or file. Affected Modicon M340 CPU (part numbers BMXP34*) versions: All versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Modicon M340 CPU (part numbers BMXP34*) you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Schneider Electric | Modicon M340 CPU (part numbers BMXP34*) | All versions | Not stated |
| Schneider Electric | Modicon MC80 (part numbers BMKC80) | All versions | Not stated |
| Schneider Electric | Modicon Momentum Unity M1E Processor (171CBU*) | All Versions | Not stated |
| Schneider Electric | modicon_m340 | all versions | Not stated |
| Schneider Electric | modicon_mc80 | all versions | Not stated |
| Schneider Electric | modicon_momentum_unity_m1e_processor | all versions | Not stated |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (se.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.5 | High | CNA (se.com) |
| CVSS 3.1 | 7.5 | High | CNA (se.com) |
Official description
CWE-924: Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability exists that could cause retrieval of password hash that could lead to denial of service and loss of confidentiality and integrity of controllers. To be successful, the attacker needs to inject themself inside the logical network while a valid user uploads or downloads a project file into the controller.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Enforcement of Message Integrity During Transmission in a Communication Channel
The product establishes a communication channel with an endpoint and receives a message from that endpoint, but it does not sufficiently ensure that the message was not modified during transmission.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Modicon M340 CPU (part numbers BMXP34*)
- 8.1 High severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
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