# CVE-2021-30473: Use after free in n/a

> A use-after-free vulnerability in libaom allows attackers to execute arbitrary code or cause denial of service via crafted media files.

- **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:** 3 Aug 2024
- **Also known as:** ALPINE-CVE-2021-30473, DEBIAN-CVE-2021-30473, GHSA-jr38-ch73-ccgx, SUSE-SU-2022:1436-1, UBUNTU-CVE-2021-30473

## What is CVE-2021-30473?

CVE-2021-30473 is a critical use after free vulnerability in Fedoraproject Fedora, published on 6 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

aom_image.c in libaom in AOMedia before 2021-04-07 frees memory that is not located on the heap.

Weakness: CWE-763 (Release of Invalid Pointer or Reference)

## Which versions are affected by CVE-2021-30473?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libaom` | SUSE:Linux Enterprise Module for Desktop Applications 15 SP3 | All versions | 1.0.0-150200.3.12.1 |
| `libaom` | SUSE:Linux Enterprise Real Time 15 SP2 | All versions | 1.0.0-150200.3.12.1 |
| `libaom` | openSUSE:Leap 15.3 | All versions | 1.0.0-150200.3.12.1 |
| `libaom` | openSUSE:Leap 15.4 | All versions | 1.0.0-150200.3.12.1 |

Products: Aomedia Aomedia, Fedoraproject Fedora.

## How do I fix CVE-2021-30473?

Upgrade to a fixed version.

## Is CVE-2021-30473 being exploited?

There is no known exploitation of CVE-2021-30473 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2021-30475](https://insights.sbomify.com/CVE-2021-30475/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-30474](https://insights.sbomify.com/CVE-2021-30474/): Use after free in n/a (critical 9.8)
- [CVE-2023-6879](https://insights.sbomify.com/CVE-2023-6879/): heap buffer overflow in libaom (critical 9.0)
- [CVE-2020-36129](https://insights.sbomify.com/CVE-2020-36129/): Memory corruption in n/a (high 8.8)
- [CVE-2020-36131](https://insights.sbomify.com/CVE-2020-36131/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-30473 and fix it if it is affected.

What it is: CVE-2021-30473 is a critical use after free vulnerability in Fedoraproject Fedora, 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-2021-30473 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-30473/ (Markdown: https://insights.sbomify.com/CVE-2021-30473/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-30473
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-30473
- OSV: https://osv.dev/vulnerability/CVE-2021-30473

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-30473/
Summaries are generated and may contain mistakes; the official description above is the record.