CVE-2024-40762
📋 TL;DR
This vulnerability in SonicOS SSLVPN uses a weak random number generator for authentication tokens, allowing attackers to predict tokens and bypass authentication. It affects SonicWall firewall devices with SSLVPN enabled. The high CVSS score reflects the potential for complete system compromise.
💻 Affected Systems
- SonicWall firewalls with SSLVPN capability
⚠️ 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 authentication bypass allowing unauthorized access to internal networks, data exfiltration, and lateral movement.
Likely Case
Unauthorized VPN access leading to credential theft, network reconnaissance, and potential ransomware deployment.
If Mitigated
Limited impact with proper network segmentation, multi-factor authentication, and monitoring in place.
🎯 Exploit Status
Exploitation requires predicting authentication tokens, which may be feasible with weak PRNG; no public exploit code known yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check SonicWall advisory SNWLID-2025-0003 for specific patched versions
Vendor Advisory: https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2025-0003
Restart Required: Yes
Instructions:
1. Access SonicWall management interface. 2. Check for firmware updates. 3. Apply the latest patch from SonicWall. 4. Reboot the device as required.
🔧 Temporary Workarounds
Disable SSLVPN
allTemporarily disable SSLVPN service to prevent exploitation until patching.
Navigate to VPN > SSL-VPN in SonicOS interface and disable
Implement Network Controls
allRestrict SSLVPN access to trusted IP ranges using firewall rules.
Configure access rules in SonicOS to limit SSLVPN connections
🧯 If You Can't Patch
- Isolate affected devices from critical networks using segmentation.
- Enable multi-factor authentication for VPN access to add an extra layer of security.
🔍 How to Verify
Check if Vulnerable:
Check SonicOS version and SSLVPN status in device management interface; compare with patched versions in SonicWall advisory.Check Version:
Log into SonicOS interface and check System > Status for firmware version.Verify Fix Applied:
Verify firmware version matches patched release from SonicWall and test SSLVPN functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual SSLVPN authentication patterns, multiple failed logins followed by success from same IP
Network Indicators:
- Anomalous VPN connections from unexpected locations or IPs
SIEM Query:
source="sonicwall" AND (event_type="vpn_auth" AND result="success") | stats count by src_ip | where count > threshold