CVE-2021-39842: Adobe Acrobat Reader DC messageHandler.OnMessage Use-After-Free Vulnerability

Published Sep 29, 2021
·
Updated

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 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.

Affected Software

24 affected components
Adobe Acrobat>=20.001.30005<=20.004.30006
Adobe Acrobat Reader>=20.001.30005<=20.004.30006
Apple macOS
Microsoft Windows
Adobe Acrobat DC>=15.008.20082<=21.005.20058
Adobe Acrobat Reader DC>=15.008.20082<=21.005.20058
Adobe Acrobat DC>=15.008.20082<=21.005.20060
Adobe Acrobat Reader DC>=15.008.20082<=21.005.20060
Adobe Acrobat>=17.011.30059<=17.011.30199
Adobe Acrobat Reader>=17.011.30059<=17.011.30199
All of the following
Any of the following
Adobe Acrobat>=20.001.30005<=20.004.30006
Adobe Acrobat Reader>=20.001.30005<=20.004.30006
Any of the following
Apple macOS
Microsoft Windows
All of the following
Any of the following
Adobe Acrobat DC>=15.008.20082<=21.005.20058
Adobe Acrobat Reader DC>=15.008.20082<=21.005.20058
Apple macOS
All of the following
Any of the following
Adobe Acrobat DC>=15.008.20082<=21.005.20060
Adobe Acrobat Reader DC>=15.008.20082<=21.005.20060
Microsoft Windows
All of the following
Any of the following
Adobe Acrobat>=17.011.30059<=17.011.30199
Adobe Acrobat Reader>=17.011.30059<=17.011.30199
Any of the following
Apple macOS
Microsoft Windows

Event History

Sep 29, 2021
CVE Published
via MITRE·03:38 PM
Data Sourced
via MITRE·03:38 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:15 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2021-39842?

CVE-2021-39842 has been rated as critical due to its potential for arbitrary code execution.

2

How do I fix CVE-2021-39842?

To mitigate CVE-2021-39842, update Adobe Acrobat Reader DC to the latest version.

3

Which versions are affected by CVE-2021-39842?

CVE-2021-39842 affects Adobe Acrobat Reader DC versions 2021.005.20060 and earlier, 2020.004.30006 and earlier, and 2017.011.30199 and earlier.

4

Can CVE-2021-39842 be exploited remotely?

Yes, CVE-2021-39842 can potentially be exploited remotely if a user opens a malicious PDF file.

5

What are the potential consequences of CVE-2021-39842 exploitation?

Exploitation of CVE-2021-39842 could lead to arbitrary code execution, allowing an attacker to gain control over the affected system.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203