CVE-2021-41688 Use after free in n/a

High 7.5 Published 28 Jun 2022 Updated 3 Nov 2025

A double free vulnerability in DCMTK's dcmqrdb program allows attackers to cause a denial of service via specific requests.

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

What is CVE-2021-41688?

CVE-2021-41688 is a high-severity use after free vulnerability in n/a, published on 28 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

DCMTK through 3.6.6 does not handle memory free properly. The object in the program is free but its address is still used in other locations. Sending specific requests to the dcmqrdb program will incur a double free. An attacker can use it to launch a DoS attack.

Weakness: CWE-415

Which versions are affected by CVE-2021-41688?

It affects 1 product.

Products include Offis Dcmtk.

How do I fix CVE-2021-41688?

Apply the vendor's patch.

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-2021-41688 being exploited?

There is no known exploitation of CVE-2021-41688 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2021-41688, GHSA-fwff-cx6h-wxmq, UBUNTU-CVE-2021-41688.