CVE-2021-20204 Use after free in getdata

What is CVE-2021-20204?

CVE-2021-20204 is a critical use after free vulnerability in Debian Debian Linux, published on 6 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A heap memory corruption problem (use after free) can be triggered in libgetdata v0.10.0 when processing maliciously crafted dirfile databases. This degrades the confidentiality, integrity and availability of third-party software that uses libgetdata as a library. This vulnerability may lead to arbitrary code execution or privilege escalation depending on input/skills of attacker.

Weakness: CWE-416, CWE-119

Which versions are affected by CVE-2021-20204?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Getdata Project Getdata.

How do I fix CVE-2021-20204?

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-2021-20204 being exploited?

There is no known exploitation of CVE-2021-20204 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-20204, DLA-2660-1, GHSA-mjc7-82x6-3544, UBUNTU-CVE-2021-20204, openSUSE-SU-2021:1645-1.