# CVE-2020-24698: Use after free in n/a

> Remote attackers can trigger a double-free via crafted GSS-TSIG queries, potentially causing crashes or arbitrary code execution in PowerDNS Authoritative.

- **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:** 2 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-24698, GHSA-h4gh-3gv9-c4vm

## What is CVE-2020-24698?

CVE-2020-24698 is a critical use after free vulnerability in n/a, published on 2 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in PowerDNS Authoritative through 4.3.0 when --enable-experimental-gss-tsig is used. A remote, unauthenticated attacker might be able to cause a double-free, leading to a crash or possibly arbitrary code execution. by sending crafted queries with a GSS-TSIG signature.

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2020-24698?

It affects 1 product.


Products: Powerdns Authoritative.

## How do I fix CVE-2020-24698?

Apply the vendor's patch.

## Is CVE-2020-24698 being exploited?

There is no known exploitation of CVE-2020-24698 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-24696](https://insights.sbomify.com/CVE-2020-24696/): Race condition in n/a (high 8.1)
- [CVE-2015-5470](https://insights.sbomify.com/CVE-2015-5470/): Denial of service in n/a (high 7.8)
- [CVE-2026-42001](https://insights.sbomify.com/CVE-2026-42001/): Insufficient Validation of Autoprimary SOA Queries (high 7.5)
- [CVE-2020-24697](https://insights.sbomify.com/CVE-2020-24697/): Denial of service in n/a (high 7.5)
- [CVE-2016-5426](https://insights.sbomify.com/CVE-2016-5426/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-24698 and fix it if it is affected.

What it is: CVE-2020-24698 is a critical use after free vulnerability in n/a, published on 2 Oct 2020. 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-2020-24698 in the wild and no public exploit code.

Affected product: n/a. 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-2020-24698/ (Markdown: https://insights.sbomify.com/CVE-2020-24698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-24698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-24698
- OSV: https://osv.dev/vulnerability/CVE-2020-24698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-24698/
Summaries are generated and may contain mistakes; the official description above is the record.