CVE-2025-2746
📋 TL;DR
An authentication bypass vulnerability in Kentico Xperience's Staging Sync Server allows attackers to bypass digest authentication by exploiting empty SHA1 username handling. This enables unauthorized administrative access and potential control over CMS objects. Affects Xperience through version 13.0.172.
💻 Affected Systems
- Kentico Xperience CMS
📦 What is this software?
Xperience by Kentico
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to gain administrative control, modify content, execute arbitrary code, and potentially pivot to other systems.
Likely Case
Unauthorized administrative access leading to content manipulation, data theft, and potential privilege escalation within the CMS.
If Mitigated
Limited impact if proper network segmentation and authentication controls prevent access to vulnerable endpoints.
🎯 Exploit Status
Multiple public exploit references and detailed technical analysis available. CISA has added to Known Exploited Vulnerabilities catalog.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 13.0.173 or later
Vendor Advisory: https://devnet.kentico.com/download/hotfixes
Restart Required: Yes
Instructions:
1. Download hotfix from Kentico DevNet. 2. Apply patch to affected Xperience installation. 3. Restart application/services. 4. Verify version is 13.0.173 or higher.
🔧 Temporary Workarounds
Disable Staging Sync Server
windowsTemporarily disable the vulnerable Staging Sync Server component if not essential.
Stop-StagingSyncServer service or disable in IIS
Network Access Control
allRestrict network access to Staging Sync Server endpoints using firewall rules.
Add firewall rule to block external access to Staging Sync Server port
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Staging Sync Server from untrusted networks
- Enable additional authentication layers and monitor for suspicious authentication attempts
🔍 How to Verify
Check if Vulnerable:
Check Xperience version in Admin interface or web.config file. If version ≤13.0.172 and Staging Sync Server is enabled, system is vulnerable.Check Version:
Check Admin interface → System → About or examine web.config for version informationVerify Fix Applied:
Verify version is ≥13.0.173 and test authentication to Staging Sync Server endpoints.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts with empty usernames
- Unusual administrative activity from unexpected IPs
- Authentication bypass patterns in Staging Sync logs
Network Indicators:
- Unauthorized requests to /StagingSync/ endpoints
- Authentication bypass attempts using digest auth
SIEM Query:
source="*kentico*" AND (event="authentication_failure" OR event="admin_access") AND (username="" OR username=null)🔗 References
- https://devnet.kentico.com/download/hotfixes
- https://github.com/watchtowrlabs/kentico-xperience13-AuthBypass-wt-2025-0011
- https://labs.watchtowr.com/bypassing-authentication-like-its-the-90s-pre-auth-rce-chain-s-in-kentico-xperience-cms/
- https://www.vulncheck.com/advisories/kentico-xperience-staging-sync-server-digest-password-authentication-bypass
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-2746
