Overview
CVE-2025-55074 is a low-severity information disclosure vulnerability affecting the Agents plugin within Mattermost. Specifically, versions 10.11.x up to 10.11.3 and 10.5.x up to 10.5.11 are vulnerable. This flaw allows unauthorized users to determine when other users had read channels by observing channel member objects. While the information exposed is limited, it can still be leveraged in certain attack scenarios.
Technical Details
The vulnerability stems from a failure to properly enforce access permissions on the Agents plugin’s API endpoints. This lack of proper access control allows unauthorized users to query channel member objects and, as a result, infer when other users have accessed specific channels. The vulnerability is rooted in the logic that handles requests related to channel member information within the plugin. The exact endpoint and the parameters involved are not explicitly stated but the outcome is unauthorized access to the ‘read’ status of users on channels.
CVSS Analysis
- Severity: LOW
- CVSS Score: 3.0
A CVSS score of 3.0 indicates a low severity vulnerability. While the impact is limited to information disclosure, it’s important to address to prevent potential exploitation in conjunction with other vulnerabilities or social engineering tactics.
Possible Impact
The exploitation of CVE-2025-55074 can lead to the following potential impacts:
- Information Disclosure: Unauthorized users can gain knowledge of when specific users have read channels.
- Privacy Concerns: Even seemingly benign information can reveal patterns of behavior and preferences, potentially leading to privacy breaches.
- Attack Vector: This vulnerability could be used as part of a larger attack strategy to gather intelligence about user activity within the Mattermost environment.
Mitigation or Patch Steps
To mitigate the risk associated with CVE-2025-55074, it is strongly recommended to upgrade your Mattermost instance to a version that includes the fix. This includes upgrading beyond versions 10.11.3 and 10.5.11. Refer to the official Mattermost security update notes for specific instructions and available patched versions. Applying the latest security patches is crucial to protecting your Mattermost deployment.
- Backup Your Data: Before upgrading, create a backup of your Mattermost database and configuration files.
- Upgrade Mattermost: Follow the official Mattermost upgrade guide to upgrade your instance to the latest stable version.
- Verify the Patch: After upgrading, verify that the Agents plugin is functioning correctly and that the vulnerability is no longer present.
