CVE-2025-48007
📋 TL;DR
This CVE describes an improper output encoding vulnerability in BlueSpice's Avatars extension that allows cross-site scripting (XSS) attacks. Attackers can inject malicious scripts that execute in victims' browsers when viewing specially crafted content. This affects BlueSpice installations from version 5 through 5.1.1.
💻 Affected Systems
- BlueSpice MediaWiki with BlueSpiceAvatars extension
📦 What is this software?
Bluespice by Hallowelt
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, perform actions as authenticated users, deface websites, or redirect users to malicious sites, potentially leading to complete account compromise.
Likely Case
Attackers with access to create or edit content could embed malicious scripts that execute when other users view that content, potentially stealing session data or performing unauthorized actions.
If Mitigated
With proper input validation and output encoding, the risk is limited to users who intentionally bypass security controls or use unsanitized inputs.
🎯 Exploit Status
Exploitation requires the ability to create or modify content that gets processed by the vulnerable Avatars extension, typically requiring some level of authenticated access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: BlueSpice 5.1.2 or later
Vendor Advisory: https://en.wiki.bluespice.com/wiki/Security:Security_Advisories/BSSA-2025-05
Restart Required: No
Instructions:
1. Update BlueSpice to version 5.1.2 or later. 2. If using the BlueSpiceAvatars extension separately, ensure it's updated to the patched version. 3. Clear any caches after updating.
🔧 Temporary Workarounds
Disable BlueSpiceAvatars Extension
allTemporarily disable the vulnerable extension until patching is possible
Edit LocalSettings.php and add: wfLoadExtension('BlueSpiceAvatars'); // Comment out or remove this line
Implement Content Security Policy
allAdd CSP headers to mitigate XSS impact by restricting script execution
Add to web server config or .htaccess: Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
For Apache: Header always set Content-Security-Policy "default-src 'self'; script-src 'self'"
🧯 If You Can't Patch
- Implement strict input validation on all user-controllable fields that interact with the Avatars extension
- Enable read-only mode for user content areas until patching is possible
🔍 How to Verify
Check if Vulnerable:
Check BlueSpice version in the administration interface or by examining the LocalSettings.php file for version informationCheck Version:
Check BlueSpice version in admin panel or grep for 'wgBlueSpice' in LocalSettings.phpVerify Fix Applied:
Verify BlueSpice version is 5.1.2 or later and test avatar functionality with test XSS payloads📡 Detection & Monitoring
Log Indicators:
- Unusual content submissions containing script tags or JavaScript in avatar-related fields
- Multiple failed attempts to submit malformed avatar data
Network Indicators:
- Unexpected script loads from avatar content URLs
- Suspicious POST requests to avatar upload endpoints
SIEM Query:
source="webserver.log" AND (uri="/api.php" OR uri="/index.php") AND (message="*<script>*" OR message="*javascript:*") AND (message="*avatar*" OR message="*BlueSpiceAvatars*")