CVE-2023-42821 Explained : Impact and Mitigation

This article provides detailed information about CVE-2023-42821, a vulnerability in the

github.com/gomarkdown/markdown

Go library.

Understanding CVE-2023-42821

This section delves into the nature and impact of the CVE-2023-42821 vulnerability in the Go library.

What is CVE-2023-42821?

The vulnerability in the

github.com/gomarkdown/markdown

library allows for an out-of-bounds read when parsing citations, potentially leading to a denial of service attack.

The Impact of CVE-2023-42821

The impact of this vulnerability is rated as HIGH, with a CVSS base score of 7.5. It poses a risk of causing a denial of service due to out-of-bounds read vulnerability.

Technical Details of CVE-2023-42821

This section provides technical details about the vulnerability, affected systems, and exploit mechanism.

Vulnerability Description

Parsing malformed markdown input with the

parser.Mmark

extension before pseudoversion

0.0.0-20230922105210-14b16010c2ee

can trigger an out-of-bounds read vulnerability in the

github.com/gomarkdown/markdown

library. The issue occurs in the

citation.go

file, specifically at line 69.

Affected Systems and Versions

The vulnerability affects versions of the

github.com/gomarkdown/markdown

library before pseudoversion

0.0.0-20230922105210-14b16010c2ee

.

Exploitation Mechanism

To exploit the vulnerability, the parser must have the

parser.Mmark

extension set, triggering an out-of-bounds read when attempting to access an element past its length.

Mitigation and Prevention

This section outlines steps to mitigate the CVE-2023-42821 vulnerability in the

github.com/gomarkdown/markdown

library.

Immediate Steps to Take

Users are advised to update to commit

14b16010c2ee7ff33a940a541d993bd043a88940

or a higher version to patch the vulnerability.

Long-Term Security Practices

Ensure regular updates and monitoring for security advisories to protect against similar vulnerabilities in the future.

Patching and Updates

Apply patches and updates provided by the

github.com/gomarkdown/markdown

library to address the out-of-bounds read vulnerability.