CVE-2025-43918
📋 TL;DR
This vulnerability allows attackers to obtain trusted TLS certificates for domains they don't control by exploiting a flaw in SSL.com's domain validation process. When using validation method 3.2.2.4.14, attackers can use their email address domain to request certificates for that domain without proving administrative control. This affects organizations using SSL.com certificates issued before April 19, 2025.
💻 Affected Systems
- SSL.com Certificate Authority services
⚠️ 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
Attackers obtain trusted certificates for legitimate domains, enabling man-in-the-middle attacks, phishing sites with valid HTTPS, and bypassing security controls that rely on certificate validation.
Likely Case
Phishing campaigns using legitimate-looking HTTPS sites, interception of encrypted traffic for targeted domains, and impersonation of legitimate services.
If Mitigated
Limited impact if organizations monitor certificate transparency logs and have proper certificate pinning or revocation checking in place.
🎯 Exploit Status
Exploitation requires the attacker to have an email address at the target domain and access to SSL.com's certificate request system. The technique is well-documented in the validation flaw.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2025-04-19 and later
Vendor Advisory: https://bugzilla.mozilla.org/show_bug.cgi?id=1961406
Restart Required: No
Instructions:
1. Contact SSL.com to revoke any potentially compromised certificates. 2. Request re-issuance of certificates using updated validation methods. 3. Ensure all new certificates are issued after April 19, 2025.
🔧 Temporary Workarounds
Disable email-based domain validation
allConfigure SSL.com to use alternative domain validation methods (DNS or HTTP-based) instead of method 3.2.2.4.14
Certificate Transparency monitoring
allMonitor certificate transparency logs for unauthorized certificates issued for your domains
Use tools like certstream or monitor crt.sh for your domains
🧯 If You Can't Patch
- Implement certificate pinning (HPKP or application-level pinning) to reject unauthorized certificates
- Deploy network monitoring to detect unexpected certificate changes or man-in-the-middle attempts
🔍 How to Verify
Check if Vulnerable:
Check certificate issuance date and validation method in certificate details. Certificates issued before 2025-04-19 using email validation may be vulnerable.Check Version:
openssl x509 -in certificate.crt -text -noout | grep -A 5 'X509v3 Subject Alternative Name' and check issuance dateVerify Fix Applied:
Verify new certificates are issued after 2025-04-19 and use validation methods other than 3.2.2.4.14. Check certificate transparency logs for unauthorized issuances.📡 Detection & Monitoring
Log Indicators:
- Unexpected certificate issuance events in CA logs
- Multiple certificate requests for same domain from different email addresses
Network Indicators:
- HTTPS connections presenting unexpected certificates
- Certificate transparency log alerts for your domains
SIEM Query:
source="ssl_ca_logs" AND (event_type="certificate_issued" AND validation_method="3.2.2.4.14")