CVE-2021-39839 Adobe Acrobat Reader DC AcroForm getItemAt Use-After-Free Remote Code Execution Vulnerability

What is CVE-2021-39839?

CVE-2021-39839 is a high-severity use after free vulnerability in Adobe Acrobat, published on 29 Sep 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 Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a use-after-free vulnerability in the processing of the AcroForm getItem action 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

Which versions are affected by CVE-2021-39839?

It affects 4 products.

Products include Adobe Acrobat, Adobe Acrobat Dc, Adobe Acrobat Reader, Adobe Acrobat Reader Dc.

How do I fix CVE-2021-39839?

No fix has been published for CVE-2021-39839 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-39839 being exploited?

There is no known exploitation of CVE-2021-39839 in the wild and no public exploit code.

Other vulnerabilities in Adobe Acrobat

• CVE-2021-28550 Adobe Acrobat and Reader Use-After-Free Exploited Critical 9.6
• CVE-2021-21017 Adobe Acrobat and Reader Heap-based Buffer Overflow Exploited High 8.8
• CVE-2014-0546 Adobe Reader and Acrobat Sandbox Bypass Exploited High 8.8
• CVE-2014-0496 Adobe Reader and Acrobat Use-After-Free Exploited High 8.8
• CVE-2013-3346 Adobe Reader and Acrobat Memory Corruption Exploited High 8.8

All Adobe Acrobat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-8gj7-p588-576j.