CVE-2024-5872
📋 TL;DR
This vulnerability in Arista EOS allows specially crafted packets with incorrect VLAN tags to be incorrectly processed by the control plane, potentially causing route instability and incorrect multicast route learning. It affects Arista EOS platforms running vulnerable versions. Network administrators managing Arista switches should be concerned.
💻 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
Sustained network instability causing widespread routing flaps, incorrect multicast routing leading to traffic blackholing, and potential denial of service for critical network services.
Likely Case
Intermittent route flapping and temporary multicast routing issues causing localized network performance degradation and connectivity problems.
If Mitigated
Minimal impact with proper network segmentation and access controls limiting exposure to malicious packets.
🎯 Exploit Status
Exploitation requires crafting specific malformed packets but does not require authentication. No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Arista advisory for specific fixed versions
Vendor Advisory: https://www.arista.com/en/support/advisories-notices/security-advisory/20649-security-advisory-0106
Restart Required: Yes
Instructions:
1. Review Arista advisory for affected versions. 2. Download and install the fixed EOS version from Arista support. 3. Schedule maintenance window for switch reboot. 4. Apply update following Arista's upgrade procedures.
🔧 Temporary Workarounds
Implement ACL filtering
allApply access control lists to filter malformed VLAN packets before they reach vulnerable interfaces
ip access-list standard VLAN-FILTER
deny any vlan malformed
permit any
interface EthernetX
ip access-group VLAN-FILTER in
Network segmentation
allSegment network to limit exposure of vulnerable interfaces to untrusted traffic
🧯 If You Can't Patch
- Implement strict ingress filtering on all interfaces to block malformed VLAN packets
- Isolate vulnerable switches from untrusted networks and implement network monitoring for anomalous routing behavior
🔍 How to Verify
Check if Vulnerable:
Check EOS version with 'show version' and compare against affected versions in Arista advisoryCheck Version:
show version | include Software image versionVerify Fix Applied:
Verify installed version matches fixed version from advisory and monitor for routing stability📡 Detection & Monitoring
Log Indicators:
- Unexpected route flaps in routing tables
- Abnormal BGP/OSPF neighbor state changes
- Multicast routing table inconsistencies
Network Indicators:
- Increased routing protocol updates
- Unstable network paths
- Multicast traffic anomalies
SIEM Query:
source="arista-switch" AND ("route flap" OR "neighbor down" OR "multicast route change")