CVE-2020-26305 in CommonRegexJS
Summary
by MITRE • 10/26/2024
CommonRegexJS is a CommonRegex port for JavaScript. All available versions contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, no known patches are available.
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Analysis
by VulDB Data Team • 11/14/2024
CommonRegexJS represents a JavaScript implementation of the popular CommonRegex library that provides pre-built regular expressions for common patterns such as email addresses, phone numbers, and IP addresses. This library serves as a convenient utility for developers who need to validate various data formats without crafting complex regular expressions from scratch. The vulnerability identified in CVE-2020-26305 affects all versions of this JavaScript library and stems from the inclusion of regular expressions that are susceptible to Regular Expression Denial of Service attacks. The core technical flaw lies in the design of specific regex patterns within the library that can be manipulated to cause catastrophic backtracking behavior when processing maliciously crafted input strings. When an attacker provides input designed to trigger the vulnerable patterns, the regular expression engine enters into a state of exponential time complexity where it repeatedly backtracks through the same input positions, leading to significant performance degradation or complete system unresponsiveness. This vulnerability operates at the intersection of CWE-400, which addresses improper handling of regular expressions, and specifically manifests as a ReDoS vector that can be exploited through the ATT&CK technique T1210 - Exploitation of Remote Services. The operational impact of this vulnerability is substantial as it affects any application that utilizes CommonRegexJS for input validation or data parsing, potentially allowing attackers to consume excessive computational resources and cause denial of service conditions. The absence of available patches at the time of publication means that affected systems remain vulnerable until developers migrate to alternative libraries or implement custom workarounds. Organizations using this library should immediately assess their attack surface and consider implementing input validation layers, rate limiting, or alternative validation libraries that do not contain vulnerable regular expressions. The vulnerability demonstrates how seemingly innocuous utility libraries can contain critical security flaws that affect the broader ecosystem of applications depending on them, highlighting the importance of thorough security reviews for all third-party dependencies in software supply chains.