Kentico Xperience Staging Sync Server Authentication Bypass and Remote Code Execution (CVE-2025-2746)
Executive & SecOps Summary
SECOPS ASSESSMENTKentico Xperience versions up to and including 13.0.172
Attackers can bypass authentication to gain administrative control, potentially leading to full system compromise and Remote Code Execution (RCE)
Apply the official hotfix immediately, or restrict access to the Staging Sync Server endpoint via IP whitelisting
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
Apply the official hotfix provided by Kentico. If you manage dependencies via NuGet, update your packages using the Package Manager Console:
# Update Kentico Xperience Libraries via NuGet Package Manager Console
Update-Package Kentico.Xperience.Libraries -Version 13.0.1732. Temporary Workaround & Hardening Configuration
If patching cannot be performed immediately, restrict access to the Staging Sync Server endpoint (/CMSPages/Staging/SyncServer.asmx) in your web.config to trusted IP addresses only.
<!-- Restricting access to the Staging Sync Server endpoint in web.config -->
<configuration>
<location path='CMSPages/Staging/SyncServer.asmx'>
<system.webServer>
<security>
<ipSecurity allowUnlisted='false'>
<clear />
<!-- Allow only trusted internal synchronization server IP -->
<add ipAddress='10.0.1.50' subnetMask='255.255.255.255' allowed='true' />
</ipSecurity>
</security>
</system.webServer>
</location>
</configuration>3. Log Audit & IoC Verification Commands
Use the following PowerShell script to inspect IIS logs for suspicious requests targeting the Staging Sync Server endpoint that returned a successful status code.
# Search IIS logs for successful requests to the SyncServer endpoint
$LogPath = 'C:\inetpub\logs\LogFiles\W3SVC1\*'
Select-String -Path $LogPath -Pattern 'SyncServer.asmx' | Where-Object { $_ -match ' 200 ' } | Select-Object -First 50Block Exploits Instantly with Managed Virtual Patching Rules
Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2025-2746) is a critical authentication bypass residing in the Staging Sync Server module of Kentico Xperience. The root cause lies in the improper handling of empty SHA1 usernames during digest authentication. Due to flawed validation logic, the application fails to properly reject empty or malformed cryptographic digests, allowing an unauthenticated attacker to establish an authenticated administrative session.
2. Exploitation Mechanics & Attack Scenario
An attacker initiates the exploit by sending a specially crafted HTTP request to the Staging Sync Server's digest authentication endpoint. The request contains an empty SHA1 hash in place of the username parameter. Instead of rejecting this anomalous input, the authentication backend processes it incorrectly, treating the validation as successful and granting administrative access. Once authenticated, the attacker can manipulate administrative objects, upload malicious payloads, and execute arbitrary code on the hosting server.
3. Infrastructure & Business Impact
With a CVSS score of 9.8 (Critical) and its inclusion in the CISA KEV catalog, this vulnerability poses an immediate threat to enterprise environments. Successful exploitation allows complete takeover of the CMS infrastructure, leading to data exfiltration, website defacement, and lateral movement within the corporate network.
Official Vendor Advisories & References
An authentication bypass vulnerability in Kentico Xperience allows authentication bypass via the Staging Sync Server password handling of empty SHA1 usernames in digest authentication. Authentication bypass allows an attacker to control administrative objects.This issue affects Xperience through 13.0.172.
Frequently Asked SecOps Questions (CVE-2025-2746)
FAQQ1. How critical is CVE-2025-2746 and is it actively exploited in the wild?
CVE-2025-2746 is rated CVSS 9.8 (CRITICAL) with a 30-day EPSS exploitation probability of 74.1%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2025-2746?
Primary impacted vendors include kentico across xperience. Scope summary: All installations of Kentico Xperience up to and including version 13.0.172 with Staging Sync Server enabled
Q3. What temporary mitigations or workarounds exist for CVE-2025-2746 before patching?
[Mitigation] Apply the official hotfix immediately, or restrict access to the Staging Sync Server endpoint via IP whitelisting Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
Generate an Internal Engineering Notice or CISO Report for CVE-2025-2746
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