# CVE-2021-42721: Adobe Bridge Use After Free could lead to Arbitrary code execution

> A use-after-free vulnerability in Adobe Bridge allows arbitrary code execution if a user opens a malicious file.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 16 Nov 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-5cwc-v53c-rj65

## What is CVE-2021-42721?

CVE-2021-42721 is a high-severity use after free vulnerability in Adobe Media Encoder, published on 16 Nov 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Acrobat Bridge versions 11.1.1 and earlier are affected by a use-after-free vulnerability in the processing of Format event actions that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-42721?

It affects 1 product.


Products: Adobe Media Encoder.

## How do I fix CVE-2021-42721?

No fix has been published for CVE-2021-42721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42721 being exploited?

There is no known exploitation of CVE-2021-42721 in the wild and no public exploit code.

## Other vulnerabilities in Adobe Media Encoder

- [CVE-2019-8246](https://insights.sbomify.com/CVE-2019-8246/): Memory corruption in Adobe Media Encoder (critical 9.8)
- [CVE-2019-7842](https://insights.sbomify.com/CVE-2019-7842/): Use after free in Adobe Media Encoder (high 8.8)
- [CVE-2026-47971](https://insights.sbomify.com/CVE-2026-47971/): Media Encoder | Stack-based Buffer Overflow (CWE-121) (high 7.8)
- [CVE-2026-47976](https://insights.sbomify.com/CVE-2026-47976/): Media Encoder | Out-of-bounds Write (CWE-787) (high 7.8)
- [CVE-2026-48366](https://insights.sbomify.com/CVE-2026-48366/): Media Encoder | Out-of-bounds Write (CWE-787) (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42721 and fix it if it is affected.

What it is: CVE-2021-42721 is a high-severity use after free vulnerability in Adobe Media Encoder, published on 16 Nov 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-42721 in the wild and no public exploit code.

Affected product: Adobe Media Encoder. 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-2021-42721/ (Markdown: https://insights.sbomify.com/CVE-2021-42721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42721
- OSV: https://osv.dev/vulnerability/CVE-2021-42721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42721/
Summaries are generated and may contain mistakes; the official description above is the record.