CVE-2021-34842 : Vulnerability Insights and Analysis

This CVE-2021-34842 article provides an overview of a vulnerability found in Foxit PDF Reader version 11.0.0.49893. The vulnerability, assigned to Mat Powell of Trend Micro Zero Day Initiative, allows remote attackers to execute arbitrary code on affected installations. Read on to understand the impact, technical details, and mitigation steps related to CVE-2021-34842.

Understanding CVE-2021-34842

CVE-2021-34842 is a critical vulnerability in Foxit PDF Reader version 11.0.0.49893, discovered by Mat Powell of Trend Micro Zero Day Initiative.

What is CVE-2021-34842?

This vulnerability enables remote attackers to execute arbitrary code on affected installations of Foxit PDF Reader 11.0.0.49893. User interaction is required to exploit this vulnerability by visiting a malicious page or opening a malicious file. The flaw lies in the handling of Annotation objects, where the lack of validating object existence before performing operations allows attackers to execute code in the current process.

The Impact of CVE-2021-34842

The CVSS v3.0 base score for CVE-2021-34842 is 7.8, indicating a high severity level. The attack complexity is low, but the confidentiality, integrity, and availability impacts are all high. No privileges are required, but user interaction is necessary for exploitation.

Technical Details of CVE-2021-34842

Vulnerability Description

CVE-2021-34842 is classified as CWE-416: Use After Free – attackers can manipulate Annotation objects to execute arbitrary code on the target system.

Affected Systems and Versions

Foxit PDF Reader version 11.0.0.49893 is affected by this vulnerability.

Exploitation Mechanism

Remote attackers exploit this vulnerability by convincing users to interact with malicious files or pages, triggering the execution of arbitrary code.

Mitigation and Prevention

Taking immediate action and adopting long-term security practices are crucial in addressing CVE-2021-34842. Here are the steps to mitigate the vulnerability:

Immediate Steps to Take

Users should avoid accessing untrusted websites or opening suspicious files to prevent exploitation of this vulnerability.

Long-Term Security Practices

Regularly update Foxit PDF Reader to the latest version to apply security patches and improvements.

Patching and Updates

Stay informed about security bulletins from Foxit (https://www.foxit.com/support/security-bulletins.html) and advisories from Trend Micro Zero Day Initiative (https://www.zerodayinitiative.com/advisories/ZDI-21-924/) to protect against CVE-2021-34842.