CVE-2021-33586 Use after free in n/a

Medium 4.3 Published 27 May 2021 Updated 3 Aug 2024

A remote attacker can access recently deallocated memory via malformed PONG messages, potentially leading to information disclosure or crashes.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2021-33586?

CVE-2021-33586 is a medium-severity use after free vulnerability in n/a, published on 27 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

InspIRCd 3.8.0 through 3.9.x before 3.10.0 allows any user (able to connect to the server) to access recently deallocated memory, aka the "malformed PONG" issue.

Weakness: CWE-732

Which versions are affected by CVE-2021-33586?

It affects 1 product.

Products include Inspircd Inspircd.

How do I fix CVE-2021-33586?

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-2021-33586 being exploited?

There is no known exploitation of CVE-2021-33586 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2021-33586, GHSA-mjhp-8mjg-4p7m.