# WEBrick Improper Input Validation vulnerability

Advisory record · `GHSA-6mq2-37j5-w6r6`

- **Identifiers:** `GHSA-6mq2-37j5-w6r6` · `CVE-2009-4492`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **Weakness (CWE):** [CWE-20](https://cwe.mitre.org/data/definitions/20.html)
- **Tags:** [CWE-20](https://agentprime.io/advisories/tag/cwe-20.md)
- **Published:** 24 Oct 2017
- **Updated:** 22 May 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Oct 2017, 18:33 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `webrick` (RubyGems): affected `<1.4.0`; fixed in `1.4.0`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.16, the 96th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 24 Oct 2017. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-6mq2-37j5-w6r6](https://github.com/advisories/GHSA-6mq2-37j5-w6r6)
- [OSV: GHSA-6mq2-37j5-w6r6](https://osv.dev/vulnerability/GHSA-6mq2-37j5-w6r6)
- <https://nvd.nist.gov/vuln/detail/CVE-2009-4492>
- <https://github.com/advisories/GHSA-6mq2-37j5-w6r6>
- <https://github.com/ruby/webrick>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2009-4492.yml>
- <https://web.archive.org/web/20100113155532/http://www.vupen.com/english/advisories/2010/0089>
- <https://web.archive.org/web/20100815010948/http://secunia.com/advisories/37949>
- <https://web.archive.org/web/20170402100552/http://securitytracker.com/id?1023429>
- <https://web.archive.org/web/20170908140655/http://www.securityfocus.com/archive/1/508830/100/0/threaded>
- <https://web.archive.org/web/20200228145937/http://www.securityfocus.com/bid/37710>
- <http://www.redhat.com/support/errata/RHSA-2011-0908.html>
- <http://www.redhat.com/support/errata/RHSA-2011-0909.html>
- <http://www.ruby-lang.org/en/news/2010/01/10/webrick-escape-sequence-injection>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-6mq2-37j5-w6r6>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-6mq2-37j5-w6r6/>. Everything for agents: <https://agentprime.io/llms.txt>.