CVE-2025-20248
📋 TL;DR
This vulnerability allows authenticated local attackers with root-system privileges to bypass Cisco IOS XR Software image signature verification and load unsigned software. It affects Cisco IOS XR devices during the installation process of .iso files. Attackers can modify .iso contents to install unauthorized software on compromised devices.
💻 Affected Systems
- Cisco IOS XR Software
⚠️ 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
An attacker with root access could install malicious firmware, backdoors, or unauthorized software, potentially gaining persistent control over network infrastructure devices.
Likely Case
Insider threats or compromised administrator accounts could install modified software to bypass security controls or establish persistence.
If Mitigated
With proper access controls and monitoring, exploitation would be limited to authorized administrators, reducing overall risk.
🎯 Exploit Status
Requires root-system privileges and ability to modify .iso files before installation
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Cisco advisory for fixed releases
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xrsig-UY4zRUCG
Restart Required: No
Instructions:
1. Review Cisco advisory for affected versions 2. Upgrade to fixed release 3. Verify image integrity before installation
🔧 Temporary Workarounds
Strict Access Control
allLimit root-system privileges to trusted personnel only
Image Integrity Verification
allVerify .iso file integrity and signatures before installation
🧯 If You Can't Patch
- Implement strict access controls for root-system privileges
- Monitor for unauthorized software installation attempts
🔍 How to Verify
Check if Vulnerable:
Check Cisco advisory for affected IOS XR versions and compare to your device versionCheck Version:
show versionVerify Fix Applied:
Verify device is running fixed IOS XR version from Cisco advisory📡 Detection & Monitoring
Log Indicators:
- Unauthorized software installation attempts
- Modified .iso file installations
- Image verification failures
Network Indicators:
- Unexpected device behavior after software updates
SIEM Query:
Search for IOS XR installation logs with verification failures or unauthorized software loads