CVE-2025-54458
📋 TL;DR
The Mattermost Confluence Plugin before version 1.5.0 has an authorization bypass vulnerability where it fails to verify user permissions when creating Confluence space subscriptions. Attackers can subscribe to Confluence spaces they shouldn't have access to, potentially exposing sensitive information. This affects organizations using Mattermost with the vulnerable Confluence plugin integration.
💻 Affected Systems
- Mattermost Confluence Plugin
📦 What is this software?
Confluence by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
Attackers could subscribe to all Confluence spaces, gaining unauthorized access to sensitive documentation, project plans, and confidential information across the organization.
Likely Case
Privileged users or attackers with valid credentials could access Confluence spaces beyond their authorized scope, leading to information disclosure of internal documentation.
If Mitigated
With proper network segmentation and access controls, impact is limited to unauthorized subscription creation without direct data exfiltration.
🎯 Exploit Status
Exploitation requires authenticated access to Mattermost and knowledge of Confluence space identifiers. No public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.0 or 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 plugin is active and functioning.
🔧 Temporary Workarounds
Disable Confluence Plugin
allTemporarily disable the vulnerable plugin until patching is possible
mmctl plugin disable com.mattermost.confluence
Restrict Plugin Access
allLimit which users can access and configure the Confluence plugin
🧯 If You Can't Patch
- Implement strict access controls and monitor for unusual subscription activity
- Segment Mattermost and Confluence networks to limit lateral movement
🔍 How to Verify
Check if Vulnerable:
Check Confluence plugin version in Mattermost System Console > Plugin ManagementCheck Version:
mmctl plugin list | grep confluenceVerify Fix Applied:
Confirm plugin version is 1.5.0 or higher and test subscription creation with unauthorized user📡 Detection & Monitoring
Log Indicators:
- Unusual subscription creation events
- Failed authorization checks in plugin logs
- Multiple subscription attempts from single user
Network Indicators:
- Increased API calls to Confluence subscription endpoints
- Unusual patterns in Mattermost-Confluence communication
SIEM Query:
source="mattermost" AND "create subscription" AND ("confluence" OR "plugin")