CVE-2025-1118
📋 TL;DR
A vulnerability in grub2 allows attackers to bypass lockdown mode and read arbitrary memory contents using the dump command. This could expose sensitive information like cryptographic signatures and salts. Systems using grub2 with lockdown mode enabled are affected.
💻 Affected Systems
- grub2
⚠️ 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
Attackers extract cryptographic keys, passwords, or other sensitive data from memory, leading to complete system compromise or data breach.
Likely Case
Attackers with physical or console access extract limited sensitive information from memory, potentially enabling further attacks.
If Mitigated
With proper access controls and monitoring, impact is limited to information disclosure from memory accessible during boot.
🎯 Exploit Status
Exploitation requires console or physical access during boot process. Simple command execution in grub shell.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor-specific updates (e.g., grub2 packages with fixes from Red Hat, Ubuntu, etc.)
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2025-1118
Restart Required: Yes
Instructions:
1. Update grub2 package using your distribution's package manager. 2. Regenerate grub configuration. 3. Reboot system to apply changes.
🔧 Temporary Workarounds
Disable grub2 lockdown mode
linuxRemove or disable lockdown mode configuration to prevent exploitation (reduces security but eliminates vulnerability)
Edit /etc/default/grub and remove GRUB_ENABLE_LOCKDOWN=1 or similar lockdown settings
Run update-grub or grub2-mkconfig
🧯 If You Can't Patch
- Restrict physical and console access to systems during boot process
- Implement full disk encryption to protect memory contents at rest
🔍 How to Verify
Check if Vulnerable:
Check if grub2 lockdown mode is enabled and version is unpatched: grep -i lockdown /etc/default/grub && rpm -q grub2 (or equivalent for your distribution)Check Version:
rpm -q grub2 (RHEL/CentOS/Fedora) or dpkg -l | grep grub (Debian/Ubuntu)Verify Fix Applied:
Verify grub2 package version matches patched version from vendor advisory and lockdown mode still functions📡 Detection & Monitoring
Log Indicators:
- Console access logs during boot time
- Grub shell activity in system logs
Network Indicators:
- None - local exploitation only
SIEM Query:
Search for console access events or boot process anomalies around system startup times