Detect Kentico Xperience CMS Authentication Bypass (CVE-2025-2747) in Splunk
Detects exploitation of CVE-2025-2747, an authentication bypass vulnerability (CWE-288) in Kentico Xperience CMS. Attackers can access protected administrative or content management endpoints via alternate paths or channels without valid credentials, enabling unauthorized access to sensitive CMS functionality. This vulnerability is actively exploited in the wild and listed in CISA KEV.
MITRE ATT&CK
SPL Detection Query
index=web sourcetype IN ("iis", "access_combined", "nginx:plus:kv")
| where uri_path IN ["/CMSPages/", "/CMSModules/", "/Admin/", "/KenticoCMS/", "/CMS/", "/cms/"] OR like(uri_path, "%CMSPages%") OR like(uri_path, "%CMSModules%") OR like(uri_path, "%SiteManager%") OR like(uri_path, "%CMSDesk%")
| where status IN ("200", "201", "302")
| where cs_username IN ("-", "", "anonymous") OR isnull(cs_username)
| eval is_admin_path=if(like(uri_path, "%SiteManager%") OR like(uri_path, "%CMSDesk%") OR like(uri_path, "%Admin%"), 1, 0)
| stats count AS request_count, values(uri_path) AS accessed_paths, values(status) AS statuses, dc(uri_path) AS distinct_paths BY src_ip, cs_username, is_admin_path
| where request_count > 1
| sort -is_admin_path, -request_countDetects anonymous or unauthenticated successful access to Kentico Xperience CMS administrative paths, aggregated by source IP to surface bypass attempts and post-exploit enumeration.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Public resource endpoints under /CMSPages/ that are intentionally unauthenticated
- Monitoring or uptime check services probing CMS health endpoints
- Content delivery networks caching and requesting CMS-served assets
- Internal vulnerability scanners performing authenticated scans that appear anonymous in logs
Other platforms for CVE-2025-2747
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Kentico CMS Unauthenticated Admin Path Access Simulation
Expected signal: IIS access logs will record HTTP GET requests to each tested path with the source IP of the test host; requests will appear with no authenticated username (cs_username = '-').
- Test 2Alternate Channel Authentication Bypass via Parameter Manipulation
Expected signal: Web server logs capture each variant request with full URI including query string; WAF logs may flag path traversal patterns in the query string.
- Test 3Post-Bypass Webshell Upload Simulation via CMS File Manager
Expected signal: Windows Security Event Log will show file creation event (Event ID 4663) for test_detection.aspx under the CMS web root; Sysmon Event ID 11 (FileCreate) will capture the new .aspx file creation with the IIS worker process (w3wp.exe) as the creator.
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