CVE-2025-61553
📋 TL;DR
This vulnerability allows local attackers to trigger an out-of-bounds write in BitVisor's VirtIO network device emulation, potentially causing hypervisor crashes or enabling arbitrary code execution. It affects BitVisor installations from May 2020 to July 2025 where attackers have local access to guest VMs.
💻 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
Guest-to-host privilege escalation leading to full hypervisor compromise and control over all VMs on the host
Likely Case
Denial of service through hypervisor crash, disrupting all VMs on the affected host
If Mitigated
Isolated crash of single VM if hypervisor protections prevent escalation
🎯 Exploit Status
Requires local access to guest VM and knowledge of PCI configuration space manipulation
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 480907 (2025-07-06) and later
Vendor Advisory: https://github.com/retrage/advisories/blob/main/CVE-2025-61553/README.md
Restart Required: Yes
Instructions:
1. Update BitVisor to commit 480907 or later. 2. Rebuild and reinstall BitVisor. 3. Reboot all affected hypervisor hosts.
🔧 Temporary Workarounds
Disable VirtIO network devices
allRemove or disable VirtIO network device emulation for guest VMs
Modify VM configuration to use alternative network interfaces (e.g., e1000) instead of VirtIO
Restrict PCI configuration space access
allLimit guest VM access to PCI configuration space through hypervisor controls
Configure BitVisor to restrict PCI configuration space operations from guest VMs
🧯 If You Can't Patch
- Isolate affected hypervisors from critical infrastructure and other sensitive systems
- Implement strict access controls to prevent unauthorized local access to guest VMs
🔍 How to Verify
Check if Vulnerable:
Check BitVisor commit hash: if between 108df6 and 480907 (exclusive), system is vulnerableCheck Version:
bitvisor --version or check /proc/version for BitVisor commit informationVerify Fix Applied:
Verify BitVisor is running commit 480907 or later using version check command📡 Detection & Monitoring
Log Indicators:
- Hypervisor crash logs
- Unexpected PCI configuration space access attempts from guest VMs
- Kernel panic or watchdog timeouts in hypervisor
Network Indicators:
- Sudden loss of connectivity to all VMs on a host
- Hypervisor management interface becoming unresponsive
SIEM Query:
source="hypervisor_logs" AND ("panic" OR "crash" OR "watchdog") AND "BitVisor"