CVE-2025-44004
📋 TL;DR
The Mattermost Confluence Plugin before version 1.5.0 has an authorization bypass vulnerability that allows attackers to create unauthorized channel subscriptions via API calls. This affects organizations using the vulnerable plugin to integrate Mattermost with Confluence. Attackers could subscribe channels to unauthorized content without proper permissions.
💻 Affected Systems
- Mattermost Confluence Plugin
📦 What is this software?
Confluence by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
Attackers could subscribe sensitive Mattermost channels to unauthorized Confluence content, potentially exposing confidential information or disrupting communications.
Likely Case
Unauthorized users create unwanted channel subscriptions, leading to spam notifications or exposure of non-sensitive content.
If Mitigated
With proper network segmentation and access controls, impact is limited to internal users who already have some level of access.
🎯 Exploit Status
Exploitation requires API access but no authentication for the specific endpoint. Attackers need to know the API endpoint structure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.0
Vendor Advisory: https://mattermost.com/security-updates
Restart Required: Yes
Instructions:
1. Update Mattermost Confluence Plugin to version 1.5.0 or later via Mattermost Marketplace or manual installation. 2. Restart Mattermost server. 3. Verify plugin version in System Console > Plugins.
🔧 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 isolate Mattermost from untrusted networks
- Enable audit logging for all plugin API calls and monitor for unauthorized subscription attempts
🔍 How to Verify
Check if Vulnerable:
Check plugin version in Mattermost System Console > Plugins > Confluence Plugin. If version is below 1.5.0, system is vulnerable.Check Version:
mmctl plugin list | grep confluenceVerify Fix Applied:
Verify plugin version is 1.5.0 or higher in System Console > Plugins. Test that unauthorized users cannot create channel subscriptions.📡 Detection & Monitoring
Log Indicators:
- Unauthorized POST requests to /plugins/com.mattermost.confluence/api/v1/subscriptions
- Failed authorization logs for subscription creation
Network Indicators:
- Unusual API calls to Confluence plugin endpoints from unauthorized IPs
- Spike in subscription creation requests
SIEM Query:
source="mattermost" AND ("com.mattermost.confluence" OR "subscription") AND status="success" AND user NOT IN [authorized_users]