mjolnir: Lack of Administrator Control over Security
CVE-2025-24024 is a critical-severity lack of administrator control over security vulnerability in mjolnir from Matrix-org, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected mjolnir versions: = 1.9.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of mjolnir you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Matrix-org | mjolnir | = 1.9.0 | 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
- 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
- HighData or code can be modified at will.
- 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:H/A:H. Scored by CNA (github.com).
Official description
Mjolnir is a moderation tool for Matrix. Mjolnir v1.9.0 responds to management commands from any room the bot is member of. This can allow users who aren't operators of the bot to use the bot's functions, including server administration components if enabled. Version 1.9.1 reverts the feature that introduced the bug, and version 1.9.2 reintroduces the feature safely. Downgrading to version 1.8.3 is recommended if upgrading to 1.9.1 or higher isn't possible.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Lack of Administrator Control over Security
The product uses security features in a way that prevents the product's administrator from tailoring security settings to reflect the environment in which the product is being used.
More Lack of Administrator Control over Security vulnerabilities (CWE-671)
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
Patches and release notes
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