CVE-2025-40805
📋 TL;DR
This critical vulnerability allows unauthenticated remote attackers to bypass authentication on specific API endpoints and impersonate legitimate users. Affected Siemens devices with exposed vulnerable endpoints are at risk, particularly when attackers have obtained legitimate user identities.
💻 Affected Systems
- Siemens industrial devices (specific models not detailed in provided references)
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, access sensitive data, modify configurations, or disrupt operations as any legitimate user.
Likely Case
Unauthorized access to sensitive data, configuration changes, or privilege escalation leading to lateral movement within the network.
If Mitigated
Limited impact if proper network segmentation, authentication controls, and monitoring are in place to detect and block unauthorized access attempts.
🎯 Exploit Status
Exploitation requires knowledge of legitimate user identities but does not require authentication to vulnerable endpoints.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Siemens advisories for specific fixed versions
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-001536.html
Restart Required: Yes
Instructions:
1. Review Siemens advisories SSA-001536 and SSA-014678. 2. Identify affected products and versions. 3. Apply vendor-provided patches or firmware updates. 4. Restart affected devices as required.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices from untrusted networks and restrict access to vulnerable API endpoints.
Access Control Lists
allImplement strict network ACLs to limit access to vulnerable endpoints to authorized IP addresses only.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected devices
- Deploy intrusion detection systems to monitor for authentication bypass attempts
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against Siemens advisories and test if unauthenticated access to API endpoints is possible.Check Version:
Device-specific command (consult Siemens documentation for exact command)Verify Fix Applied:
Verify firmware version matches patched version from Siemens advisories and test that authentication is properly enforced on all API endpoints.📡 Detection & Monitoring
Log Indicators:
- Unauthenticated API access attempts
- Authentication bypass patterns in access logs
- Unusual user activity from unexpected sources
Network Indicators:
- Unusual API traffic patterns
- Authentication requests to vulnerable endpoints without credentials
SIEM Query:
source_ip OUTSIDE trusted_networks AND (http_path CONTAINS '/api/vulnerable_endpoint' OR similar_patterns) AND authentication_status='failed' OR 'bypassed'