CVE-2025-14946
📋 TL;DR
A vulnerability in libnbd allows arbitrary code execution when processing malicious URIs. Attackers can exploit this by tricking libnbd into opening specially crafted URIs where hostnames starting with '-o' are misinterpreted as SSH arguments instead of hostnames. This affects users and applications that utilize libnbd to handle network block device connections.
💻 Affected Systems
- libnbd
⚠️ 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
Full arbitrary code execution with the privileges of the user running libnbd, potentially leading to complete system compromise.
Likely Case
Limited code execution in the context of the libnbd user, potentially allowing file system access, data exfiltration, or further privilege escalation.
If Mitigated
No impact if proper input validation and patching are implemented, or if libnbd is not exposed to untrusted URI inputs.
🎯 Exploit Status
Exploitation requires social engineering or automated tools to feed malicious URIs to libnbd. No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.24.1
Vendor Advisory: https://libguestfs.org/libnbd-release-notes-1.24.1.html#Security
Restart Required: Yes
Instructions:
1. Download libnbd version 1.24.1 or later from the official repository. 2. Compile and install the new version following standard build procedures. 3. Restart any services or applications that use libnbd to ensure the patched library is loaded.
🔧 Temporary Workarounds
Input Validation
linuxImplement strict input validation to reject URIs with hostnames starting with '-o' before passing them to libnbd.
# Example: Validate URI hostname does not start with '-o' before processing
# if [[ $uri_hostname == -* ]]; then reject; fi
Environment Hardening
linuxRun libnbd with minimal privileges and in a restricted environment to limit potential damage from exploitation.
# Use SELinux/AppArmor to restrict libnbd processes
# Run libnbd as a non-privileged user
🧯 If You Can't Patch
- Isolate systems using libnbd from untrusted networks and users.
- Monitor for unusual process activity or network connections originating from libnbd processes.
🔍 How to Verify
Check if Vulnerable:
Check the libnbd version; if it is earlier than 1.24.1, the system is vulnerable.Check Version:
nbdkit --version | grep libnbdVerify Fix Applied:
Verify that libnbd version is 1.24.1 or later and test with a safe URI to ensure functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual SSH process arguments or errors in libnbd logs related to URI parsing.
- Failed connection attempts with malformed hostnames starting with '-o'.
Network Indicators:
- Unexpected network connections from libnbd processes to external hosts.
- SSH connections with unusual command-line arguments.
SIEM Query:
Example: process.name:"libnbd" AND process.cmd_line:"-o*"