# CVE-2021-20204: Use after free in getdata

> A use-after-free vulnerability in libgetdata allows attackers to execute arbitrary code or escalate privileges via malicious dirfile databases.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 May 2021
- **Updated:** 17 Oct 2024
- **Also known as:** DEBIAN-CVE-2021-20204, DLA-2660-1, GHSA-mjc7-82x6-3544, UBUNTU-CVE-2021-20204, openSUSE-SU-2021:1645-1

## 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 (Use After Free), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-20204?

It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `getdata` | openSUSE:Leap 15.2 | All versions | 0.11.0-lp152.4.3.1 |

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

## How do I fix CVE-2021-20204?

Upgrade to a fixed version.

## 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](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20204 and fix it if it is affected.

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

Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-20204/ (Markdown: https://insights.sbomify.com/CVE-2021-20204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20204
- OSV: https://osv.dev/vulnerability/CVE-2021-20204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20204/
Summaries are generated and may contain mistakes; the official description above is the record.