On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indef
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
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| Arista Networks | EOS | unaffected |
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| Vendor | Product | Versions | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Arista | Eos |
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Vendor Solution
The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Important: Upgrading alone is not sufficient. The replay protection introduced by the fix is disabled by default and must be explicitly enabled with the following new global configuration command after upgrading to a remediated release: switch(config)#vrrp ipv4 authentication anti-replay CVE-2026-73443 has been fixed in the following releases: * 4.36.2F and later releases in the 4.36.x train * 4.35.6M and later releases in the 4.35.x train * 4.34.8M and later releases in the 4.34.x train * 4.33.10M and later releases in the 4.33.x train
Vendor Workaround
Exposure is limited to attackers with access to the layer 2 network segment on which VRRP is running. Restricting physical and logical access to VRRP-enabled segments (for example with port security and by not extending VRRP VLANs to untrusted access ports) reduces the attack surface. Additionally, migrating virtual routers from VRRP version 2 with authentication to VRRP version 3 removes the vulnerable code path. The below configuration shows how to configure VRRPv3 on VLAN 20: switch(config)# interface vlan 20 switch(config-if-vl20)# vrrp 1 ipv4 version 3
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.273% probability within 30 days)
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| First Time appeared |
Arista
Arista eos |
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| Vendors & Products |
Arista
Arista eos |
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| Metrics |
ssvc
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| Description | On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indefinitely. Replayed advertisements can be used to advertise stale VRRP state, for example to prevent a backup router from taking over the virtual gateway after the original master has gone down, resulting in a denial of service for hosts using the virtual gateway address. | |
| Title | On affected platforms running Arista EOS with VRRPv2 IP-AH authentication configured, an unauthenticated attacker within the same layer 2 network segment on which VRRP is running can capture a legitimate authenticated VRRP advertisement and replay it indef | |
| Weaknesses | CWE-294 | |
| References |
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| Metrics |
cvssV3_1
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