Detect Kentico Xperience Path Traversal and Arbitrary File Upload (CVE-2025-2749) in Microsoft Sentinel
Detects exploitation of CVE-2025-2749, a path traversal and unrestricted file upload vulnerability in Kentico Xperience CMS. Attackers can traverse directory boundaries to write arbitrary files — including web shells — to locations outside the intended upload path, enabling remote code execution on the hosting server. This CVE is listed in the CISA Known Exploited Vulnerabilities catalog.
MITRE ATT&CK
- Tactic
- Initial Access Execution Persistence
KQL Detection Query
let suspiciousExtensions = dynamic(['.aspx', '.asp', '.ashx', '.asmx', '.config', '.php', '.jsp', '.exe', '.dll', '.bat', '.cmd', '.ps1', '.sh']);
let kenticoUploadPaths = dynamic(['/kentico/', '/cmspages/', '/cmsformcontrols/', '/cmsmodules/', '/getfile/', '/uploadfile/']);
union DeviceNetworkEvents, W3CIISLog, AppServiceHTTPLogs
| where TimeGenerated >= ago(24h)
| where RequestUri has_any (kenticoUploadPaths)
| where RequestUri matches regex @"\.\.[\/\\]"
or RequestUri has "%2e%2e"
or RequestUri has "%252e"
or RequestUri has "..%2f"
or RequestUri has "..%5c"
| extend FileExt = extract(@"(\.[a-zA-Z0-9]{2,5})(?:\?|$)", 1, tolower(RequestUri))
| where FileExt in (suspiciousExtensions) or HttpMethod == "POST"
| project TimeGenerated, ClientIP, RequestUri, HttpMethod, HttpStatus, FileExt, UserAgent, SiteName
| order by TimeGenerated descDetects HTTP requests to Kentico Xperience upload endpoints containing path traversal sequences or targeting executable file extensions that may indicate CVE-2025-2749 exploitation attempts.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate file uploads by content editors using filenames that happen to contain dots
- Security scanners or vulnerability assessment tools running authorized scans against the CMS
- URL-encoded characters in legitimate multilingual content paths
Other platforms for CVE-2025-2749
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 Path Traversal Upload Simulation
Expected signal: IIS access log records a POST to /kentico/cmsformcontrols/uploader.ashx with a filename parameter containing '../..' sequences; file creation event may appear in Windows Security log under w3wp.exe
- Test 2Encoded Path Traversal Bypass Attempt
Expected signal: IIS log shows double-encoded percent sequences in the request URL; WAF logs may show allowed request if only basic traversal patterns are blocked
- Test 3Web Shell Execution Post-Exploit Simulation
Expected signal: Windows Security Event ID 4663 fires for file creation under w3wp.exe; DeviceFileEvents in Defender shows .aspx file written by w3wp.exe; subsequent HTTP GET to the shell path appears in IIS logs
Unlock Pro Content
Get the full detection package for CVE-2025-2749 including response playbook, investigation guide, and atomic red team tests.