CVE-2021-23362 : Vulnerability Insights and Analysis

Regular Expression Denial of Service (ReDoS) vulnerability in the package 'hosted-git-info' before version 3.0.8 allows attackers to launch a ReDoS attack via a regular expression shortcutMatch in index.js, leading to significant impact.

Understanding CVE-2021-23362

This CVE identifies a vulnerability in the 'hosted-git-info' package that can be exploited by attackers to cause denial of service through a ReDoS attack.

What is CVE-2021-23362?

The vulnerability arises from the use of regular expression shortcutMatch in the 'fromUrl' function in index.js in 'hosted-git-info' package versions prior to 3.0.8, resulting in a ReDoS vulnerability with polynomial worst-case time complexity.

The Impact of CVE-2021-23362

The impact of this vulnerability is rated as MEDIUM severity. An attacker can exploit this flaw to cause a denial of service by inducing high CPU consumption.

Technical Details of CVE-2021-23362

This section covers the technical details related to the vulnerability in 'hosted-git-info' package.

Vulnerability Description

The vulnerability allows attackers to trigger a ReDoS attack by exploiting the regular expression shortcutMatch, causing a significant denial of service.

Affected Systems and Versions

The 'hosted-git-info' package versions earlier than 3.0.8 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit the vulnerability by crafting malicious requests that trigger the ReDoS attack, leading to CPU exhaustion and denial of service.

Mitigation and Prevention

To address CVE-2021-23362 and prevent exploitation, follow the guidelines outlined below.

Immediate Steps to Take

Update the 'hosted-git-info' package to version 3.0.8 or above to eliminate the vulnerability.
Monitor and restrict input patterns to prevent malicious actors from triggering the ReDoS attack.

Long-Term Security Practices

Implement regular security patches and updates to stay protected against emerging vulnerabilities.
Conduct security audits and code reviews to detect and mitigate similar vulnerabilities in the future.

Patching and Updates

Refer to the following resources for patches and updates:

Patch for hosted-git-info
Hosted-git-info commits v2
Cert-portal Siemens advisory