CVE-2021-34696 Cisco ASR 900 and ASR 920 Series Aggregation Services Routers Access Control List Bypass Vulnerability

Medium 5.8 Published 23 Sep 2021 Updated 7 Nov 2024

Remote attackers can bypass Access Control Lists on Cisco ASR routers if ACLs are configured via non-CLI methods, requiring vendor patches.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-34696?

CVE-2021-34696 is a medium-severity vulnerability in Cisco Ios Xe, published on 23 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the access control list (ACL) programming of Cisco ASR 900 and ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device.

Weakness: CWE-284

Which versions are affected by CVE-2021-34696?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2021-34696?

No fix has been published for CVE-2021-34696 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-34696 being exploited?

There is no known exploitation of CVE-2021-34696 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-28xr-x3rf-rhgr.