CVE-2019-20922 : Vulnerability Insights and Analysis

Handlebars before version 4.4.5 is susceptible to Regular Expression Denial of Service (ReDoS) attacks due to its eagerness in pattern matching. Exploiting this vulnerability can lead to system resource depletion by causing the parser to enter an infinite loop.

Understanding CVE-2019-20922

Handlebars version prior to 4.4.5 is vulnerable to a specific type of denial of service attack.

What is CVE-2019-20922?

Handlebars before 4.4.5 is prone to Regular Expression Denial of Service (ReDoS) attacks. This vulnerability arises from the parser's eagerness in matching patterns, potentially causing it to get stuck in an infinite loop when processing specially crafted templates.

The Impact of CVE-2019-20922

Exploiting this vulnerability can allow malicious actors to exhaust system resources, leading to a denial of service condition.

Technical Details of CVE-2019-20922

Handlebars vulnerability details and affected systems.

Vulnerability Description

Handlebars before 4.4.5 allows Regular Expression Denial of Service (ReDoS) due to eager matching, potentially causing the parser to enter an endless loop while processing crafted templates.

Affected Systems and Versions

Affected Version: Handlebars version prior to 4.4.5

Exploitation Mechanism

Attackers can exploit the eagerness in pattern matching to craft templates that force the parser into an infinite loop, depleting system resources.

Mitigation and Prevention

Protecting systems from CVE-2019-20922.

Immediate Steps to Take

Update Handlebars to version 4.4.5 or newer to mitigate the vulnerability.
Regularly monitor system resources for unusual consumption that may indicate a ReDoS attack.

Long-Term Security Practices

Implement input validation to prevent malicious patterns from causing ReDoS vulnerabilities.
Educate developers on secure coding practices to avoid introducing similar vulnerabilities.

Patching and Updates

Apply patches and updates promptly to ensure that known vulnerabilities are addressed.