CVE-2025-61554
📋 TL;DR
A divide-by-zero vulnerability in BitVisor's VirtIO network device emulation allows local attackers to crash the host hypervisor by accessing crafted PCI configuration space. This affects BitVisor installations from May 2020 to July 2025. Only local attackers can exploit this vulnerability.
💻 Affected Systems
- BitVisor
⚠️ 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
Host hypervisor crash leading to denial of service for all virtual machines running on that host
Likely Case
Local denial of service causing temporary hypervisor unavailability
If Mitigated
Minimal impact with proper access controls preventing local attacker access
🎯 Exploit Status
Requires local access and knowledge of PCI configuration space manipulation
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit de84887f4418fcd67945b4aa4842e035bce0dfa9 or later
Vendor Advisory: https://sourceforge.net/p/bitvisor/code/ci/de84887f4418fcd67945b4aa4842e035bce0dfa9
Restart Required: No
Instructions:
1. Update BitVisor to commit de84887f4418fcd67945b4aa4842e035bce0dfa9 or later
2. Recompile and redeploy the hypervisor
3. No hypervisor restart required for patch application
🔧 Temporary Workarounds
Restrict local access
allLimit local access to hypervisor to trusted users only
Implement strict access controls and user permissions
Disable VirtIO network emulation
allUse alternative network virtualization methods if possible
Configure VMs to use different network device types
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized local access to hypervisor
- Monitor hypervisor logs for unusual PCI configuration space access attempts
🔍 How to Verify
Check if Vulnerable:
Check BitVisor commit hash: git log --oneline -1Check Version:
git log --oneline -1Verify Fix Applied:
Verify commit hash is de84887f4418fcd67945b4aa4842e035bce0dfa9 or later📡 Detection & Monitoring
Log Indicators:
- Hypervisor crash logs
- Unexpected divide-by-zero errors in hypervisor logs
- Abnormal PCI configuration space access attempts
Network Indicators:
- Sudden loss of connectivity to VMs on affected host
SIEM Query:
search 'hypervisor crash' OR 'divide by zero' AND source='bitvisor'