Mattermost: Improper Limitation of a Pathname to a Restricted Directory
CVE-2025-25279 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Mattermost, 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. Affected Mattermost versions: 10.4.0 through 10.4.1; 9.11.0 through 9.11.7; 10.3.0 through 10.3.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 24.2% chance of exploitation within 30 days, which is in the top 2.11% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Update Mattermost Server to 9.11.8 or 10.2.3 or 10.3.3 or 10.4.2, whichever matches your release line, or a later version.
- Read the advisory on mattermost.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 |
|---|---|---|---|
| Mattermost | Mattermost | 10.4.0 through 10.4.1; 9.11.0 through 9.11.7; 10.3.0 through 10.3.2; 10.2.0 through 10.2.2 | Not stated |
| Mattermost | Mattermost Server | 9.11.0 up to, but not including, 9.11.8; 10.2.0 up to, but not including, 10.2.3; 10.3.0 up to, but not including, 10.3.3; 10.4.0 up to, but not including, 10.4.2 | 9.11.8, 10.2.3, 10.3.3, 10.4.2 |
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
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.9 | Critical | CNA (mattermost.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
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
Advisories
Other vulnerabilities in Mattermost
- 8.0 High severity
- 7.1 High severity
- 9.3 Critical severity
- 7.1 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 9.1 Critical severity
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.5 High severity
- 7.5 High severity
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