CVE-2021-42836 Explained : Impact and Mitigation

GJSON before 1.9.3 allows a ReDoS (regular expression denial of service) attack.

Understanding CVE-2021-42836

GJSON version prior to 1.9.3 is vulnerable to a ReDoS attack.

What is CVE-2021-42836?

CVE-2021-42836 refers to the vulnerability in GJSON that permits a ReDoS attack, potentially leading to a denial of service condition.

The Impact of CVE-2021-42836

The vulnerability in GJSON could result in a significant impact on system availability and performance due to the denial of service attack capability.

Technical Details of CVE-2021-42836

This section outlines the technical aspects of the CVE.

Vulnerability Description

CVE ID: CVE-2021-42836
Vulnerability Type: ReDoS (Regular Expression Denial of Service)
Affected Software: GJSON
Affected Version: versions before 1.9.3

Affected Systems and Versions

Software: GJSON
Versions Affected: All versions before 1.9.3

Exploitation Mechanism

The vulnerability can be exploited by crafting malicious regular expressions that cause the GJSON parser to exhibit inefficient behavior, resulting in a denial of service condition.

Mitigation and Prevention

Protective measures against CVE-2021-42836.

Immediate Steps to Take

Update GJSON to version 1.9.3 or newer to mitigate the vulnerability.
Regularly monitor and analyze system logs for any unusual activity that may indicate exploitation attempts.
Implement network filtering to restrict access to GJSON services.

Long-Term Security Practices

Conduct regular security assessments and penetration testing to identify and address vulnerabilities proactively.
Educate developers and system administrators on secure coding practices and the risks of regular expression vulnerabilities.

Patching and Updates

Stay informed about security updates and patches released by the GJSON maintainers.
Apply patches promptly to ensure that known vulnerabilities are remediated in a timely manner.