CVE-2021-31756 Memory corruption in n/a

Critical 9.8 Published 7 May 2021 Updated 3 Aug 2024

Attackers can execute arbitrary code on Tenda AC11 routers via a stack buffer overflow in the setwanType endpoint.

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-2021-31756?

CVE-2021-31756 is a critical memory corruption vulnerability in n/a, published on 7 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered on Tenda AC11 devices with firmware through 02.03.01.104_CN. A stack buffer overflow vulnerability in /gofrom/setwanType allows attackers to execute arbitrary code on the system via a crafted post request. This occurs when input vector controlled by malicious attack get copied to the stack variable.

Weakness: CWE-787

Which versions are affected by CVE-2021-31756?

It affects 1 product.

Products include Tenda Ac11 Firmware.

How do I fix CVE-2021-31756?

No fix has been published for CVE-2021-31756 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-2021-31756 being exploited?

There is no known exploitation of CVE-2021-31756 in the wild and no public exploit code.

Sources

Also known as GHSA-cm66-w4c7-wx9w.