CVE-2021-43306 Explained : Impact and Mitigation

CVE-2021-43306, titled 'Exponential ReDoS in jquery-validation,' was published on 2022-05-29. The vulnerability affects the jquery-validation package versions less than 1.19.4.

Understanding CVE-2021-43306

CVE-2021-43306 is a vulnerability in the jquery-validation npm package that can lead to an exponential Regular Expression Denial of Service (ReDoS) when malicious input is supplied to the url2 method.

What is CVE-2021-43306?

An attacker exploiting this vulnerability can trigger an Exponential ReDoS in the jquery-validation package by providing crafted input to the url2 method, leading to a denial of service condition.

The Impact of CVE-2021-43306

CVSS Base Score: 5.9 (Medium Severity)
Attack Vector: Network
Attack Complexity: High
Availability Impact: High
Confidentiality Impact: None
Integrity Impact: None
Privileges Required: None

Technical Details of CVE-2021-43306

The technical details of CVE-2021-43306 provide insights into the vulnerability and its implications.

Vulnerability Description

The vulnerability allows for an attacker to launch an Exponential ReDoS attack by exploiting the jquery-validation package's url2 method.

Affected Systems and Versions

Affected Product: jquery-validation
Affected Versions:
Less than 1.19.4

Exploitation Mechanism

The vulnerability is triggered when an attacker supplies specially crafted input to the url2 method, causing excessive backtracking and leading to a denial of service condition.

Mitigation and Prevention

Effective mitigation strategies are crucial to address and prevent CVE-2021-43306 from being exploited.

Immediate Steps to Take

Upgrade jquery-validation to version 1.19.4 or newer to mitigate the vulnerability.

Long-Term Security Practices

Regularly update dependencies to ensure the use of the latest secure versions.

Patching and Updates

Stay informed about security advisories and promptly apply patches to address known vulnerabilities.