Detect CVE-2025-2746: Kentico Xperience CMS Authentication Bypass in Google Chronicle
Detects exploitation of CVE-2025-2746, an authentication bypass vulnerability (CWE-288) in Kentico Xperience CMS that allows attackers to access protected resources via alternate paths or channels without valid credentials. This vulnerability is actively exploited in the wild (CISA KEV).
MITRE ATT&CK
YARA-L Detection Query
rule cve_2025_2746_kentico_auth_bypass {
meta:
author = "df00tech Detection Engineering"
description = "Detects authentication bypass exploitation of CVE-2025-2746 in Kentico Xperience CMS via unauthenticated access to protected CMS paths"
severity = "CRITICAL"
priority = "HIGH"
reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-2746"
cve = "CVE-2025-2746"
mitre_attack_tactic = "Initial Access"
mitre_attack_technique = "T1190"
events:
$e.metadata.event_type = "NETWORK_HTTP"
$e.network.http.response_code in (200, 201, 302)
(
re.regex($e.network.http.request_url, `/CMSPages/|/CMSModules/|/CMSAdminControls/|/CMS/|/Admin/`)
)
not re.regex($e.network.http.request_url, `(?i)(login|logon|signin|auth|forgot)`)
(
not $e.principal.user.userid != ""
or $e.principal.user.userid = "-"
or $e.principal.user.userid = "anonymous"
)
match:
$e.principal.ip over 5m
condition:
#e >= 3
}Chronicle YARA-L rule detecting repeated unauthenticated HTTP success responses from Kentico Xperience CMS administrative paths. Triggers when three or more such requests originate from the same IP within a 5-minute window, indicating active authentication bypass exploitation.
Data Sources
Required Tables
False Positives & Tuning
- Automated testing frameworks running against pre-production Kentico instances with authentication disabled
- Third-party integrations using custom authentication not tracked in standard HTTP auth fields
- Security scanners performing authorized assessments of the Kentico deployment
- Reverse proxies or API gateways forwarding requests without preserving original authentication context
Other platforms for CVE-2025-2746
Testing Methodology
Validate this detection against 4 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 1CVE-2025-2746 Authentication Bypass Path Enumeration
Expected signal: IIS access log entries showing HTTP GET requests to /CMSPages/, /CMSModules/, /CMSAdminControls/, /CMS/, and /Admin/ paths from the test host IP without a cs-username value, with HTTP response codes of 200, 302, or 401 depending on patch status.
- Test 2CVE-2025-2746 Alternate Path Channel Bypass Attempt
Expected signal: IIS logs should capture the URL-encoded and case-variant path requests. ASP.NET request normalization may cause the logged URI to differ from the requested URI — look for both raw and normalized forms in telemetry. Windows Security Event Log may show failed authorization attempts (Event ID 4625) if integrated auth is configured.
- Test 3CVE-2025-2746 Post-Exploitation CMS Account Creation Simulation
Expected signal: IIS logs showing POST request to /CMSModules/Membership/Pages/Users/User_Edit_General.aspx without authentication. Kentico CMS_EventLog table entries for user creation attempt. Windows Security Event Log entries for IIS process activity. If successful on unpatched system, CMS_User table will contain the new account.
- Test 4CVE-2025-2746 Network-Level Authentication Bypass Detection Validation
Expected signal: 10 concurrent HTTP requests to Kentico CMS paths appearing in IIS logs within a 1-second window, all from the same source IP without authentication headers. The burst pattern should appear clearly in SIEM dashboards.
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