CVE-2023-22486 Explained : Impact and Mitigation

This CVE record highlights a vulnerability in the cmark-gfm library that may lead to a denial of service due to unbounded resource exhaustion.

Understanding CVE-2023-22486

This vulnerability affects versions prior to 0.29.0.gfm.7 of the cmark-gfm library, GitHub's fork of cmark. The issue lies in a quadratic complexity bug in the handle_close_bracket function, which can result in resource exhaustion and subsequent denial of service.

What is CVE-2023-22486?

The vulnerability in CVE-2023-22486 is categorized under CWE-400 (Uncontrolled Resource Consumption) and CWE-407 (Inefficient Algorithmic Complexity). It poses a low severity threat with a base score of 3.5, according to CVSS v3.1 metrics.

The Impact of CVE-2023-22486

With low attack complexity and low impact on availability, confidentiality, and integrity, this vulnerability requires low privileges and user interaction. However, the unbounded resource exhaustion can lead to a denial of service if exploited.

Technical Details of CVE-2023-22486

The vulnerability arises from a polynomial time complexity issue specifically in the handle_close_bracket function within cmark-gfm versions earlier than 0.29.0.gfm.7. This flaw allows an attacker to exhaust resources, potentially rendering the system unresponsive.

Vulnerability Description

The vulnerability stems from inefficient algorithmic complexity within the handle_close_bracket function, leading to uncontrolled resource consumption and denial of service.

Affected Systems and Versions

The following version of cmark-gfm library is affected:

Vendor: GitHub
Product: cmark-gfm
Affected Version: < 0.29.0.gfm.7

Exploitation Mechanism

An attacker can exploit the vulnerability by crafting specific input that triggers the handle_close_bracket function in a way that consumes excessive resources, causing a denial of service condition.

Mitigation and Prevention

To address CVE-2023-22486, users and administrators are advised to take immediate steps and adopt long-term security practices to mitigate the risk of exploitation.

Immediate Steps to Take

Update the cmark-gfm library to version 0.29.0.gfm.7 or later to apply the necessary patch that mitigates the vulnerability.
Monitor system resources for any unusual spikes in resource consumption that could indicate a potential denial of service attack.

Long-Term Security Practices

Regularly update software components and libraries to ensure that known vulnerabilities are patched promptly.
Conduct thorough code reviews and security testing to identify and address potential algorithmic complexity issues.

Patching and Updates

GitHub has released a patch in version 0.29.0.gfm.7 to address the vulnerability in the handle_close_bracket function. It is crucial for users to update to this patched version to protect their systems from denial of service attacks.