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CVE-2021-28511

MEDIUM severity · CVSS 5.8 · Improper access control
5.8CVSS MEDIUM

Summary

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.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactNone
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Affected products we track (1)

EOS

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.