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Status published
High
CVE-2021-25122
Apache Tomcat h2c request mix-up
Vulnerability Description
When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
THREAT MONITOR
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Credits & Attribution
No credits recorded in the NVD database.
References
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rf6d5d57b114678d8898005faef31e9fd6d7c981fcc4ccfc3bc272fc9%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cannounce.apache.org%3E
- http://www.openwall.com/lists/oss-security/2021/03/01/1
- https://lists.apache.org/thread.html/rcd90bf36b1877e1310b87ecd14ed7bbb15da52b297efd9f0e7253a3b%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rd0463f9a5cbc02a485404c4b990f0da452e5ac5c237808edba11c947%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/03/msg00018.html
- https://www.debian.org/security/2021/dsa-4891
- 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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Affected Vendor
Apache Software Foundation
View all reports →Affected Software
Apache Tomcat
Vulnerable Versions:
Apache Tomcat 10, Apache Tomcat 9, Apache Tomcat 8.5
Timeline
Official Publish:
March 1st, 2021
Last Modified:
February 13th, 2025
Added to House:
July 21st, 2026
CVSS Vectors
V3:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N