CVE-2023-46743
📋 TL;DR
This vulnerability in XWiki's Collabora Online integration allows users with view-only permissions to gain edit access to documents when they open attachments after a user with edit rights has accessed them. The issue affects XWiki instances using application-collabora integration where document permissions are enforced. Attackers can exploit cached permission states to modify documents they shouldn't have write access to.
💻 Affected Systems
- XWiki with application-collabora integration
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Unauthorized users could modify sensitive documents, inject malicious content, or delete important information in collaborative environments.
Likely Case
Users with view-only permissions accidentally or intentionally edit documents they shouldn't have write access to, potentially causing data integrity issues.
If Mitigated
With proper access controls and monitoring, impact is limited to temporary permission escalation within active editing sessions.
🎯 Exploit Status
Exploitation requires a user with edit rights to open a document first, then a user with view-only rights accessing the same document during the active session.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3
Vendor Advisory: https://github.com/xwikisas/application-collabora/security/advisories/GHSA-mvq3-xxg2-rj57
Restart Required: Yes
Instructions:
1. Backup your XWiki instance. 2. Update application-collabora extension to version 1.3 via XWiki Extension Manager. 3. Restart XWiki application server. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Collabora Online editing
allTemporarily disable the Collabora Online integration to prevent exploitation.
Navigate to XWiki Administration > Applications > Collabora Online and disable the extension
Restrict document access
allImplement stricter document permission policies to limit potential impact.
Review and tighten document access controls in XWiki
🧯 If You Can't Patch
- Implement strict document access monitoring and alert on unusual edit patterns
- Educate users about proper document permission management and session handling
🔍 How to Verify
Check if Vulnerable:
Check application-collabora extension version in XWiki Administration > Applications. If version is below 1.3, the system is vulnerable.Check Version:
Check XWiki Administration panel or examine the extension version in the XWiki filesystem.Verify Fix Applied:
After updating to version 1.3, test that users with view-only permissions cannot edit documents when following the exploitation scenario.📡 Detection & Monitoring
Log Indicators:
- Multiple users accessing same document with different permission levels in short timeframes
- Unexpected document modifications by users with view-only roles
Network Indicators:
- Unusual Collabora Online API calls for document editing
SIEM Query:
Search for document edit events where user permission level doesn't match expected access rights