CVE-2025-44001
📋 TL;DR
The Mattermost Confluence Plugin before version 1.5.0 has an authorization bypass vulnerability where attackers can retrieve channel subscription details without proper access permissions. This affects organizations using the vulnerable plugin to integrate Mattermost with Confluence. Attackers with network access to the Mattermost instance can exploit this via API calls.
💻 Affected Systems
- Mattermost Confluence Plugin
📦 What is this software?
Confluence by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
Attackers could enumerate all channel subscriptions across the organization, potentially revealing sensitive project information, team structures, and integration details that should be access-controlled.
Likely Case
Unauthorized users accessing subscription details for channels they shouldn't have access to, potentially learning about confidential projects or team activities.
If Mitigated
Limited information disclosure about channel subscription configurations without access to actual channel content.
🎯 Exploit Status
Requires API access to the Mattermost instance and knowledge of the vulnerable endpoint. Attackers need to be able to make HTTP requests to the Get Channel Subscriptions endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.0 and later
Vendor Advisory: https://mattermost.com/security-updates
Restart Required: No
Instructions:
1. Access Mattermost System Console. 2. Navigate to Plugin Management. 3. Update Confluence Plugin to version 1.5.0 or later. 4. Verify the plugin is active and functioning correctly.
🔧 Temporary Workarounds
Disable Confluence Plugin
allTemporarily disable the vulnerable plugin until patching is possible
mmctl plugin disable com.mattermost.confluence
Restrict API Access
allImplement network controls to restrict access to Mattermost API endpoints
🧯 If You Can't Patch
- Implement strict network segmentation to limit access to Mattermost API endpoints
- Enable detailed logging for API calls to the Get Channel Subscriptions endpoint and monitor for unauthorized access
🔍 How to Verify
Check if Vulnerable:
Check the plugin version in Mattermost System Console > Plugin Management > Confluence Plugin. If version is below 1.5.0, the system is vulnerable.Check Version:
mmctl plugin list | grep confluenceVerify Fix Applied:
Verify the Confluence Plugin version shows 1.5.0 or higher in the System Console. Test that authorized users can access subscription details while unauthorized users receive proper access denied responses.📡 Detection & Monitoring
Log Indicators:
- Multiple 200 OK responses to /plugins/com.mattermost.confluence/api/v1/channel-subscriptions from unauthorized users
- Unusual patterns of API calls to subscription endpoints
Network Indicators:
- HTTP GET requests to /plugins/com.mattermost.confluence/api/v1/channel-subscriptions from unexpected IP addresses
SIEM Query:
source="mattermost" AND uri_path="/plugins/com.mattermost.confluence/api/v1/channel-subscriptions" AND response_code=200 AND user_role!="admin"