CVE-2024-6437
📋 TL;DR
This vulnerability affects Arista EOS devices configured with policy-based routing, BGP Flowspec, or interface traffic policies. It allows certain IP traffic (like IPv4 packets with IP options) to bypass configured redirect actions and be forwarded through the normal routing path instead. Only networks using these specific traffic redirection features are impacted.
💻 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
Traffic bypasses security policies and routing controls, potentially allowing unauthorized network access or data exfiltration through unintended paths.
Likely Case
Some traffic fails to follow configured redirection policies, causing routing inconsistencies and potential performance issues as packets take suboptimal paths.
If Mitigated
With proper network segmentation and monitoring, impact is limited to minor routing anomalies that can be detected and corrected.
🎯 Exploit Status
Exploitation requires ability to send specially crafted IP packets to affected devices and knowledge of network configuration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple fixed versions available - see Arista advisory for specific version requirements
Vendor Advisory: https://www.arista.com/en/support/advisories-notices/security-advisory/20689-security-advisory-0108
Restart Required: Yes
Instructions:
1. Review Arista advisory for specific fixed versions. 2. Upgrade affected devices to recommended fixed EOS version. 3. Perform controlled maintenance window for upgrade. 4. Verify configuration after upgrade.
🔧 Temporary Workarounds
Disable affected features
allRemove or disable policy-based routing, BGP Flowspec, or interface traffic policies that redirect IP traffic
show running-config | include policy-based-routing|flowspec|traffic-policy
no policy-based-routing
no flowspec
no traffic-policy
Filter IP options packets
allImplement ACLs to drop IPv4 packets with IP options at network boundaries
ip access-list extended BLOCK_IP_OPTIONS
deny ip any any option any-options
permit ip any any
🧯 If You Can't Patch
- Implement network monitoring to detect anomalous traffic patterns
- Apply strict ACLs to limit traffic to affected devices
🔍 How to Verify
Check if Vulnerable:
Check if device has PBR, BGP Flowspec, or interface traffic policies configured: 'show running-config | include policy-based-routing|flowspec|traffic-policy'Check Version:
show version | include Software image versionVerify Fix Applied:
Verify EOS version is patched: 'show version' and compare with Arista advisory fixed versions📡 Detection & Monitoring
Log Indicators:
- Unexpected routing path changes
- CPU utilization spikes from packet processing
- Policy routing rule violations
Network Indicators:
- Traffic taking unexpected network paths
- IP packets with options being processed
SIEM Query:
source="arista" AND ("policy-based-routing" OR "flowspec" OR "traffic-policy") AND ("bypass" OR "unexpected" OR "violation")