CVE-2025-62003
📋 TL;DR
BullWall Server Intrusion Protection has a timing vulnerability where MFA checks for RDP connections have a configuration-dependent delay. Remote authenticated attackers can potentially bypass detection during this window. Affects BullWall Server Intrusion Protection versions including 4.6.0.0, 4.6.0.6, 4.6.0.7, and 4.6.1.4.
💻 Affected Systems
- BullWall Server Intrusion Protection
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers bypass MFA entirely, gaining unauthorized RDP access to protected systems and potentially compromising sensitive data or deploying malware.
Likely Case
Attackers bypass MFA detection temporarily, gaining initial access that could be used for lateral movement or privilege escalation.
If Mitigated
Attackers are detected by other security controls before causing significant damage, with limited access scope.
🎯 Exploit Status
Requires authenticated access and specific timing conditions; exploitation depends on configuration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2025/va-25-352-01.json
Restart Required: No
Instructions:
Check vendor advisory for updates; monitor for official patch release.
🔧 Temporary Workarounds
Reduce MFA Delay Configuration
windowsMinimize or eliminate the configuration-dependent delay for MFA checks in BullWall settings.
Implement Network Segmentation
allRestrict RDP access to specific IP ranges and implement additional network-level authentication controls.
🧯 If You Can't Patch
- Implement additional MFA layers outside BullWall for RDP connections.
- Monitor RDP authentication logs for unusual timing patterns or failed MFA attempts.
🔍 How to Verify
Check if Vulnerable:
Check BullWall version against affected list and review MFA delay configuration settings.Check Version:
Check BullWall administration interface or documentation for version information.Verify Fix Applied:
Verify BullWall version is updated beyond affected versions and test MFA timing under simulated attack conditions.📡 Detection & Monitoring
Log Indicators:
- Unusual timing between RDP authentication and MFA completion
- Multiple RDP connections with similar timing patterns
Network Indicators:
- RDP connections that complete authentication unusually quickly
- Traffic patterns suggesting MFA bypass attempts
SIEM Query:
Search for RDP authentication events where MFA completion time is below configured threshold.