CVE-2025-8870
📋 TL;DR
This vulnerability in Arista EOS allows an attacker to cause a denial of service by triggering an unexpected device reload through specific serial console input. It affects Arista network devices running vulnerable EOS versions. The impact is limited to availability disruption rather than data compromise.
💻 Affected Systems
- Arista EOS
⚠️ 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
Persistent denial of service through repeated device reloads, causing extended network downtime and potential cascading failures in network infrastructure.
Likely Case
Temporary network disruption during device reload, requiring manual intervention to restore service, with potential configuration loss if not properly saved.
If Mitigated
Minimal impact with proper access controls limiting serial console access to authorized personnel only.
🎯 Exploit Status
Exploitation requires physical or network access to serial console; no authentication needed once console access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in EOS versions specified in Arista Security Advisory 0125
Vendor Advisory: https://www.arista.com/en/support/advisories-notices/security-advisory/22811-security-advisory-0125
Restart Required: Yes
Instructions:
1. Review Arista Security Advisory 0125 for specific fixed versions. 2. Upgrade affected devices to patched EOS version. 3. Save configuration before upgrade. 4. Schedule maintenance window for reload.
🔧 Temporary Workarounds
Restrict Serial Console Access
allLimit physical and network access to serial console ports to authorized personnel only
Implement Console Authentication
allEnable authentication on serial console interfaces if not already configured
enable
configure terminal
line console 0
login authentication default
🧯 If You Can't Patch
- Implement strict physical security controls around serial console access
- Monitor serial console logs for unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check current EOS version against vulnerable versions listed in Arista Security Advisory 0125Check Version:
show version | include Software image versionVerify Fix Applied:
Verify EOS version is updated to patched version specified in advisory📡 Detection & Monitoring
Log Indicators:
- Unexpected device reloads
- Serial console access logs showing unusual input patterns
- System logs indicating abnormal termination
Network Indicators:
- Sudden loss of connectivity to affected device
- BGP/OSPF neighbor flaps following device reload
SIEM Query:
source="arista" AND ("reload" OR "reboot" OR "crash") AND NOT user="authorized_user"