CVE-2021-1243 Cisco IOS XR Software SNMP Management Plane Protection ACL Bypass Vulnerability

Medium 5.3 Published 4 Feb 2021 Updated 8 Nov 2024

An unauthenticated remote attacker can bypass SNMP management plane protection ACLs on Cisco IOS XR devices, allowing connections to SNMP ports despite configured deny rules.

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-2021-1243?

CVE-2021-1243 is a medium-severity vulnerability in Cisco Ios Xr, published on 4 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Local Packet Transport Services (LPTS) programming of the SNMP with the management plane protection feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to allow connections despite the management plane protection that is configured to deny access to the SNMP server of an affected device. This vulnerability is due to incorrect LPTS programming when using SNMP with management plane protection. An attacker could exploit this vulnerability by connecting to an affected device using SNMP. A successful exploit could allow the attacker to connect to the device on the configured SNMP ports. Valid credentials are required to execute any of the SNMP requests.

Weakness: CWE-284

Which versions are affected by CVE-2021-1243?

It affects 1 product.

Products include Cisco Ios Xr.

How do I fix CVE-2021-1243?

No fix has been published for CVE-2021-1243 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-1243 being exploited?

There is no known exploitation of CVE-2021-1243 in the wild and no public exploit code.

All Cisco Ios Xr vulnerabilities

Sources

Also known as GHSA-w6r6-frp2-8r52.