CVE-2021-30027 Use after free in n/a

Medium 5.5 Published 29 Apr 2021 Updated 3 Aug 2024

Attackers can cause a denial of service by triggering the use of uninitialized memory via a malformed Markdown document in the md4c library.

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: Available

What is CVE-2021-30027?

CVE-2021-30027 is a medium-severity use after free vulnerability in n/a, published on 29 Apr 2021. 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

md_analyze_line in md4c.c in md4c 0.4.7 allows attackers to trigger use of uninitialized memory, and cause a denial of service via a malformed Markdown document.

Weakness: CWE-908

Which versions are affected by CVE-2021-30027?

It affects 1 product.

Products include Md4c Project Md4c.

How do I fix CVE-2021-30027?

Upgrade to a fixed version.

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-2021-30027 being exploited?

There is no known exploitation of CVE-2021-30027 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2021-30027, GHSA-9whf-9v4j-38v8, UBUNTU-CVE-2021-30027.