# CVE-2021-28545: Acrobat Reader DC Missing Support for Integrity Check

> Attackers can manipulate certified PDF data without invalidating the certification, bypassing integrity checks in Adobe Acrobat Reader.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Apr 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-4qgw-8wjq-84wr

## What is CVE-2021-28545?

CVE-2021-28545 is a high-severity vulnerability in Adobe Acrobat, published on 1 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are missing support for an integrity check. An unauthenticated attacker would have the ability to completely manipulate data in a certified PDF without invalidating the original certification. Exploitation of this issue requires user interaction in that a victim must open the tampered file.

Weakness: CWE-353 (Missing Support for Integrity Check)

## Which versions are affected by CVE-2021-28545?

It affects 4 products.


Products: Adobe Acrobat, Adobe Acrobat Dc, Adobe Acrobat Reader, Adobe Acrobat Reader Dc.

## How do I fix CVE-2021-28545?

No fix has been published for CVE-2021-28545 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28545 being exploited?

There is no known exploitation of CVE-2021-28545 in the wild and no public exploit code.

## Other vulnerabilities in Adobe Acrobat

- [CVE-2021-28550](https://insights.sbomify.com/CVE-2021-28550/): Adobe Acrobat and Reader Use-After-Free (critical 9.6, exploited in the wild)
- [CVE-2021-21017](https://insights.sbomify.com/CVE-2021-21017/): Adobe Acrobat and Reader Heap-based Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2014-0546](https://insights.sbomify.com/CVE-2014-0546/): Adobe Reader and Acrobat Sandbox Bypass (high 8.8, exploited in the wild)
- [CVE-2014-0496](https://insights.sbomify.com/CVE-2014-0496/): Adobe Reader and Acrobat Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2013-3346](https://insights.sbomify.com/CVE-2013-3346/): Adobe Reader and Acrobat Memory Corruption (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28545 and fix it if it is affected.

What it is: CVE-2021-28545 is a high-severity vulnerability in Adobe Acrobat, published on 1 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-28545 in the wild and no public exploit code.

Affected product: Adobe Acrobat. 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-2021-28545/ (Markdown: https://insights.sbomify.com/CVE-2021-28545/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28545
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28545
- OSV: https://osv.dev/vulnerability/CVE-2021-28545

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28545/
Summaries are generated and may contain mistakes; the official description above is the record.