Do not use variable for regular expressions

Metadata

ID: javascript-browser-security/regexp-non-literal

Language: JavaScript

Severity: Warning

Category: Security

Description

Regular expressions should not use a variable as an argument since an attacker may inject values and cause a regular expression denial of service (ReDoS). Instead, use a library like recheck to check that no ReDoS can be triggered by a regular expression.

Non-Compliant Code Examples

const foo = new RegExp(req.something);
const bar = new RegExp(variable);

Compliant Code Examples

const foo = new RegExp(`^\\d+-${topicId}$`);
const foo = new RegExp(/something/);
const foo = new RegExp("weofiwje");