CVE-2021-39845 : What You Need to Know

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 stack overflow vulnerability due to insecure handling of crafted PDF files.

Understanding CVE-2021-39845

This CVE involves a stack overflow vulnerability in Adobe Acrobat Reader that could lead to memory corruption.

What is CVE-2021-39845?

The vulnerability in Acrobat Reader allows an attacker to execute code by exploiting a crafted PDF file, requiring user interaction to open the file in the affected software.

The Impact of CVE-2021-39845

The vulnerability has a CVSS base score of 6.1, making it of medium severity with high availability impact.

Technical Details of CVE-2021-39845

The technical details of the vulnerability are as follows:

Vulnerability Description

Type: Stack-based Buffer Overflow (CWE-121)
User Interaction: Required
Attack Complexity: Low

Affected Systems and Versions

Affected Product: Acrobat Reader
Affected Versions:
<= 2021.005.20060
<= 2020.004.30006
<= 2017.011.30199
<= None

Exploitation Mechanism

Requires the victim to open a malicious PDF file in Acrobat Reader, triggering memory corruption.

Mitigation and Prevention

Adobe recommends the following steps to mitigate the vulnerability:

Immediate Steps to Take

Update Acrobat Reader to the latest version.
Be cautious while opening PDF files from untrusted sources.

Long-Term Security Practices

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

Patching and Updates

Apply security updates provided by Adobe to address the vulnerability effectively.