Regular Expression Denial of Service (ReDOS)
In the npm package color-string, there is a ReDos (Regular Expression Denial of Service) vulnerability regarding an exponential time complexity for
linearly increasing input lengths for hwb() color strings.
Strings reaching more than 5000 characters would see several milliseconds of processing time; strings reaching more than 50,000 characters began seeing 1500ms (1.5s) of processing time.
The cause was due to a the regular expression that parses hwb() strings - specifically, the hue value - where the integer portion of the hue value used a 0-or-more quantifier shortly thereafter followed by a 1-or-more quantifier.
This caused excessive backtracking and a cartesian scan, resulting in exponential time complexity given a linear increase in input length.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | color-string | < 1.5.5 | 1.5.5 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-29060
- https://github.com/Qix-/color-string/commit/0789e21284c33d89ebc4ab4ca6f759b9375ac9d3
- https://github.com/Qix-/color-string/releases/tag/1.5.5
- https://github.com/yetingli/PoCs/blob/main/CVE-2021-29060/Color-String.md
- https://github.com/yetingli/SaveResults/blob/main/js/color-string.js
- https://www.npmjs.com/package/color-string
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- Weakness (CWE)
CWE-770- Platform
- npm
- Package
color-string- Disclosed
- 22.06.2021
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-257v-vj4p-3w2h - CC BY 4.0
Vulnerability history: color-string
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 06.2021 09.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 1
- Medium 1
Disclosures per year
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 0
- 2025: 1
- 2026: 0
-
Regular Expression Denial of Service (ReDOS) this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.