CVE-2021-40723 : Security Advisory and Response

This article provides insights into CVE-2021-40723, focusing on an out-of-bounds read vulnerability in Acrobat Reader DC.

Understanding CVE-2021-40723

CVE-2021-40723 involves an out-of-bounds read vulnerability in Acrobat Reader DC versions that could expose sensitive memory information when exploited by an attacker.

What is CVE-2021-40723?

Acrobat Reader DC versions 2020.013.20074 and earlier, 2020.001.30018 and earlier, and 2017.011.30188 and earlier are affected by an out-of-bounds read vulnerability. This vulnerability could allow an attacker to disclose sensitive memory data by bypassing mitigations like ASLR. Successful exploitation requires user interaction, where a victim opens a malicious file.

The Impact of CVE-2021-40723

CVSS Base Score: 5.5 (Medium Severity)
Confidentiality Impact: High
Attack Complexity: Low
User Interaction: Required
Attack Vector: Local
Exploit Code Maturity: Not Defined
This vulnerability has a base and environmental severity score of 5.5, falling in the medium severity range. It could lead to data disclosure and requires user interaction for exploitation.

Technical Details of CVE-2021-40723

Acrobat Reader DC versions are impacted by a critical out-of-bounds read vulnerability, as outlined below.

Vulnerability Description

The vulnerability entails an out-of-bounds read issue in Acrobat Reader DC versions that could allow attackers to extract sensitive memory data, compromising confidentiality.

Affected Systems and Versions

Product: Acrobat Reader
Vendor: Adobe
Affected Versions:
Versions less than or equal to 2017.011.30188

Exploitation Mechanism

Attackers can leverage the vulnerability in affected versions of Acrobat Reader to access sensitive memory information, with the need for user interaction via opening a malicious file.

Mitigation and Prevention

Stay protected by following these mitigation steps.

Immediate Steps to Take

Update Acrobat Reader to the latest patched version.
Exercise caution while opening files from unknown or untrusted sources.

Long-Term Security Practices

Regularly update software and security patches.
Implement proper file validation checks to prevent malicious file execution.

Patching and Updates

Adopt a proactive approach to security by regularly applying software updates and patches released by Adobe to address vulnerabilities promptly.