CVE-2025-2747

What it actually does

CVE-2025-2747 is an authentication bypass in Kentico Xperience 13 Staging Sync Server password handling. When a staging server is configured with the affected "None" server type/password-handling path, an unauthenticated remote attacker can reach the staging synchronization interface without valid credentials and submit synchronization operations. Because staging can create, update, or delete administrative CMS objects, successful exploitation can allow attacker-controlled changes to site configuration, content objects, users, roles, permissions, templates, scheduled tasks, and other administrative objects exposed through the staging mechanism. The issue affects Xperience through 13.0.178 and has a critical CVSS score of 9.8, KEV listing, and high EPSS likelihood, indicating real-world exploitation risk.

Why it matters to the business

A vulnerable Kentico Xperience site can be remotely modified without legitimate administrator access. In business terms, an attacker may be able to change website content, create or alter privileged accounts, weaken security settings, disrupt publishing workflows, implant persistent administrative changes, or prepare the site for malware delivery or data theft. Because this vulnerability is listed in CISA KEV with a remediation due date of 2025-11-10 and has evidence of active exploitation in the wild, exposed internet-facing Kentico Xperience deployments should be treated as urgent remediation targets even if no compromise is currently known.

How an attack unfolds

An attacker first identifies a Kentico Xperience 13 instance and probes for the staging synchronization endpoint, commonly exposed under the CMS staging web service path. If the instance is running an affected version through 13.0.178 and the vulnerable Staging Sync Server password-handling path is reachable, the attacker crafts staging synchronization requests that follow the alternate unauthenticated flow associated with a server defined as type "None." Instead of supplying valid administrative credentials, the attacker abuses the flawed authentication logic to have the request accepted as a trusted staging operation. The attacker then submits synchronization payloads that create, modify, or delete administrative objects. Depending on the objects targeted, this can result in unauthorized administrator creation, role or permission changes, web content defacement, malicious configuration changes, persistence through CMS-managed objects, and follow-on access to the application or hosting environment.

How to fix it

Upgrade Kentico Xperience to a version newer than 13.0.178; based on the affected-version boundary, organizations should apply Kentico Xperience 13.0.179 or later, or the latest vendor-supported hotfix available for Xperience 13. If immediate upgrade is not possible, restrict access to the staging synchronization endpoint to trusted source IPs only, disable staging where it is not required, remove or reconfigure any staging server definitions using the affected "None" type/password handling, and block unauthenticated internet access to staging web service paths at the reverse proxy, WAF, or web server. Review all staging server configurations after patching and rotate any credentials used for staging or administration if exploitation is suspected.

How to confirm the fix worked

Confirm the installed Kentico Xperience version is later than 13.0.178, preferably the latest Xperience 13 hotfix. Validate that staging synchronization endpoints are not reachable from untrusted networks and return an expected authentication or access-denied response when requested without valid authorization. Review Kentico administration settings to ensure staging is disabled where unnecessary and that no staging server definition uses the vulnerable unauthenticated/None configuration. Use web server, WAF, and application logs to confirm that unauthenticated POST requests to staging synchronization paths are blocked after mitigation. Where possible, perform a controlled negative test from an untrusted network path: unauthenticated staging synchronization requests should fail and should not create, modify, or delete CMS objects.

Typical attack path

1. Scan internet-facing web applications for Kentico Xperience 13 indicators and exposed staging synchronization paths.
2. Confirm the presence of the Staging Sync Server web service, such as requests to the CMS staging synchronization endpoint.
3. Send crafted staging synchronization requests that exercise the vulnerable "None" server type/password-handling path.
4. Bypass normal authentication and have the staging request processed as trusted.
5. Create, update, or delete administrative objects through staging synchronization operations.
6. Use the changed administrative objects to gain persistence, alter site behavior, deface content, weaken access controls, or enable further compromise.
7. Remove or obscure evidence by deleting suspicious CMS objects, staging tasks, or application-level audit records where possible.

How to detect it

Look for evidence of unauthenticated or unusual access to Kentico staging synchronization endpoints, especially POST requests to CMS staging web service paths from internet sources, unfamiliar IP addresses, hosting providers, VPNs, or scanners. Prioritize IIS web logs, reverse proxy logs, WAF logs, EDR telemetry, Kentico event logs, Kentico staging task history, administrative audit logs, and database/application change history available through the product. Investigate any staging synchronization request that succeeded without a known deployment window, trusted source, or expected staging peer. Review Kentico administrative objects for unexplained creations or modifications after suspicious staging requests, including administrator accounts, role membership, permission changes, page templates, transformations, web parts, scheduled tasks, custom code-bearing objects, and site settings. Correlate suspicious requests with subsequent logins, content changes, file writes, application restarts, configuration changes, or outbound network activity. Because exploitation may not require conventional login events, absence of failed logins is not sufficient to rule out compromise.

• /CMSPages/Staging/SyncServer.asmx
• POST /CMSPages/Staging/SyncServer.asmx
• GET /CMSPages/Staging/SyncServer.asmx
• SyncServer.asmx
• CMSPages/Staging
• /CMSPages/Staging/
• SOAPAction:
• POST /CMSPages/Staging/SyncServer.asmx HTTP/1.1
• server type None
• Staging Sync Server
• staging synchronization
• synchronization task

What your security team should do

• Treat this as a critical, actively exploited authentication bypass and prioritize internet-facing Kentico Xperience 13 systems for immediate patching.
• Upgrade affected deployments through 13.0.178 to Kentico Xperience 13.0.179 or later, preferably the latest vendor hotfix.
• Before and after patching, restrict staging synchronization endpoints to trusted administrative or deployment networks only.
• Disable Kentico staging if it is not operationally required.
• Inventory staging server definitions and remove or reconfigure any using the affected "None" type/password-handling mode.
• Hunt for suspicious unauthenticated or unusual POST requests to Kentico staging synchronization web service paths.
• Review CMS administrative objects for unexpected users, roles, permissions, scheduled tasks, page templates, transformations, web parts, custom tables, and configuration changes.
• If exploitation is suspected, rotate Kentico administrator credentials, staging credentials, service account credentials, and any secrets stored in CMS-managed configuration.
• Preserve IIS, reverse proxy, WAF, Kentico event, and staging logs before log rotation or cleanup.
• Track KEV remediation obligations and ensure completion before the 2025-11-10 CISA deadline where applicable.