CVE-2021-34718 Cisco IOS XR Software Arbitrary File Read and Write Vulnerability

High 8.1 Published 9 Sep 2021 Updated 7 Nov 2024

Authenticated attackers can read and write arbitrary files via SCP, leading to privilege escalation and unauthorized data access on Cisco IOS XR devices.

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

What is CVE-2021-34718?

CVE-2021-34718 is a high-severity path traversal vulnerability in Cisco Ios Xr, published on 9 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability in the SSH Server process of Cisco IOS XR Software could allow an authenticated, remote attacker to overwrite and read arbitrary files on the local device. This vulnerability is due to insufficient input validation of arguments that are supplied by the user for a specific file transfer method. An attacker with lower-level privileges could exploit this vulnerability by specifying Secure Copy Protocol (SCP) parameters when authenticating to a device. A successful exploit could allow the attacker to elevate their privileges and retrieve and upload files on a device that they should not have access to.

Weakness: CWE-88

Which versions are affected by CVE-2021-34718?

It affects 1 product.

Products include Cisco Ios Xr.

How do I fix CVE-2021-34718?

No fix has been published for CVE-2021-34718 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2021-34718 being exploited?

There is no known exploitation of CVE-2021-34718 in the wild and no public exploit code.

All Cisco Ios Xr vulnerabilities

Sources

Also known as GHSA-9j7c-3668-hr3c.