CVE-2021-39853 : Security Advisory and Response

Adobe Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier), and 2017.011.30199 (and earlier) are affected by a Null pointer dereference vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve an application denial-of-service in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Understanding CVE-2021-39853

Adobe Acrobat Reader DC Null Pointer Dereference vulnerability affecting various versions.

What is CVE-2021-39853?

It is a Null Pointer Dereference vulnerability in Adobe Acrobat Reader DC versions allowing for application denial-of-service.

The Impact of CVE-2021-39853

The vulnerability carries a CVSS base score of 5.5 (Medium severity) with high availability impact.

Technical Details of CVE-2021-39853

Adobe Acrobat Reader DC vulnerability specifics.

Vulnerability Description

Type: Null Pointer Dereference (CWE-476)
Description: Adobe Acrobat Reader DC is prone to a Null Pointer Dereference flaw.

Affected Systems and Versions

Product: Acrobat Reader
Vendor: Adobe
Affected Versions: DC 2021 July, 20.0-Classic 2021 July, 17.0-Classic 2021 July, None

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Local
User Interaction: Required
Exploitation: Requires the victim to open a malicious file.

Mitigation and Prevention

Measures to address CVE-2021-39853.

Immediate Steps to Take

Update Acrobat Reader to the latest version.
Avoid opening files from untrusted sources.
Exercise caution when interacting with files of unknown origin.

Long-Term Security Practices

Regularly update software and security patches.
Implement user awareness training regarding phishing attacks and malicious files.

Patching and Updates

Adobe has released a patch addressing this vulnerability.