CVE-2021-34727 Cisco IOS XE SD-WAN Software Buffer Overflow Vulnerability

Critical 9.8 Published 23 Sep 2021 Updated 7 Nov 2024

Unauthenticated remote attackers can trigger a buffer overflow in Cisco IOS XE SD-WAN devices to execute arbitrary commands with root privileges or cause a denial of service.

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-2021-34727?

CVE-2021-34727 is a critical memory corruption vulnerability in Cisco IOS XE SD-WAN Software, 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 vDaemon process in Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected device. This vulnerability is due to insufficient bounds checking when an affected device processes traffic. An attacker could exploit this vulnerability by sending crafted traffic to the device. A successful exploit could allow the attacker to cause a buffer overflow and possibly execute arbitrary commands with root-level privileges, or cause the device to reload, which could result in a denial of service condition.

Weakness: CWE-120

Which versions are affected by CVE-2021-34727?

It affects 1 product.

Products include Cisco Ios Xe Sd-Wan.

How do I fix CVE-2021-34727?

No fix has been published for CVE-2021-34727 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-34727 being exploited?

There is no known exploitation of CVE-2021-34727 in the wild and no public exploit code.

Sources

Also known as GHSA-rxw2-fh82-mfcc.