CVE-2021-46525 Use after free in n/a

High 7.8 Published 27 Jan 2022 Updated 4 Aug 2024

A heap-use-after-free in the MJS JavaScript engine allows attackers to execute arbitrary code or cause a denial of service.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2021-46525?

CVE-2021-46525 is a high-severity use after free vulnerability in Cesanta Mjs, published on 27 Jan 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

Cesanta MJS v2.20.0 was discovered to contain a heap-use-after-free via mjs_apply at src/mjs_exec.c.

Weakness: CWE-416

Which versions are affected by CVE-2021-46525?

It affects 1 product.

Products include Cesanta Mjs.

How do I fix CVE-2021-46525?

No fix has been published for CVE-2021-46525 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-46525 being exploited?

There is no known exploitation of CVE-2021-46525 in the wild and no public exploit code.

All Cesanta Mjs vulnerabilities

Sources

Also known as GHSA-r2fp-jg3h-x57v.