Detect CVE-2025-31125: Vite Dev Server Improper Access Control in CrowdStrike LogScale
Detects exploitation of CVE-2025-31125, an improper access control vulnerability in Vite (Vitejs) dev server. The vulnerability allows unauthorized access to sensitive files outside the intended serve root, classified under CWE-200 (Information Exposure) and CWE-284 (Improper Access Control). This vulnerability is listed in CISA KEV, indicating active exploitation in the wild.
MITRE ATT&CK
- Tactic
- Initial Access Discovery Collection
LogScale Detection Query
#event_simpleName=NetworkConnectIP4 OR #event_simpleName=HttpRequest
| CommandLine = /vite|node.*server/i OR RemotePort IN (5173, 3000, 4173, 5174, 8080)
| HttpRequestUri = /\/@fs\/.*(\.\.|\.env|\/etc\/|\/proc\/|passwd|shadow)/i
OR HttpRequestUri = /\/@fs\/[A-Za-z]:/i
OR HttpRequestUri = /\/@fs\/\/(etc|home|root|proc|var)/i
| groupby([aid, ComputerName, RemoteAddressIP4, HttpRequestUri], function=count(1), alias=request_count)
| sort(request_count, order=desc)
| limit 1000CrowdStrike Falcon Query Language detection for CVE-2025-31125 exploiting Vite dev server /@fs/ path traversal via network connection telemetry and HTTP request inspection.
Data Sources
Required Tables
False Positives & Tuning
- Vite dev server processes legitimately serving files via /@fs/ for valid workspace configurations
- Security assessment tooling running against authorized targets
- Development workstations with complex Vite plugin setups accessing cross-directory resources
- Automated testing frameworks that interact with Vite dev server endpoints during CI
Other platforms for CVE-2025-31125
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 1Vite /@fs/ Path Traversal to Read /etc/passwd
Expected signal: HTTP GET request to /@fs/etc/passwd and variants logged in web server access logs; Node.js process accessing /etc/passwd on the file system; network connection from test host to port 5173
- Test 2Vite Dev Server Environment File Extraction
Expected signal: HTTP requests to /@fs/ with absolute paths to .env files; file system read events on .env and config files; response body containing environment variable content if successful
- Test 3Automated CVE-2025-31125 Exploitation Scan
Expected signal: Rapid sequential HTTP GET requests to /@fs/ endpoint with multiple sensitive path targets; consistent source IP across all requests; mix of 200 and 403 response codes; elevated request rate to Vite dev server port
Unlock Pro Content
Get the full detection package for CVE-2025-31125 including response playbook, investigation guide, and atomic red team tests.