Vulnerability · Published Aug 5, 2022 · Assigned by Arista
CVE-2021-28511This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches t ...
Medium 5.8
In plain English
A medium-severity improper access control in EOS from Arista Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).
Official description
This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches the packet flow. This could allow a host with an IP address in a range that matches the range allowed by a NAT ACL and a range denied by a Security ACL to be forwarded incorrectly as it should have been denied by the Security ACL. This can enable an ACL bypass.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Arista Networks | EOS | 4.24.0 – through 4.24.94.25.0 – through 4.25.84.26.0 – through 4.26.54.27.0 – through 4.27.3 |
Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N