CVE-2021-39840 : What You Need to Know

Adobe Acrobat Reader DC AcroForm Field Use-After-Free Remote Code Execution Vulnerability

Understanding CVE-2021-39840

Acrobat Reader DC versions 2021.005.20060 and earlier are affected by a use-after-free vulnerability that could lead to arbitrary code execution.

What is CVE-2021-39840?

Vulnerability in processing AcroForms in Acrobat Reader DC
User interaction required for exploitation by visiting malicious pages or opening malicious files

The Impact of CVE-2021-39840

CVSS Score: 7.8 (High Severity)
Attack Vector: Local
Required User Interaction: Yes
Potential Result: Arbitrary code execution

Technical Details of CVE-2021-39840

Adobe Acrobat Reader DC vulnerability specifics:

Vulnerability Description

Use-after-free flaw in processing AcroForms
Allows arbitrary code execution within user's context

Affected Systems and Versions

Acrobat Reader DC versions 2021.005.20060 and earlier
Also affects versions 2020.004.30006 and 2017.011.30199

Exploitation Mechanism

Requires user interaction like visiting malicious pages or opening infected files

Mitigation and Prevention

Immediate Steps to Take:

Update Acrobat Reader DC to the latest version
Avoid clicking on suspicious links or opening unknown files

Long-Term Security Practices:

Regularly update software and security patches
Educate users on safe browsing habits

Patching and Updates:

Adobe released a security update, visit their website for patch details