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.
https://lists.apache.org/thread.html/[email protected]%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Cannounce.tomcat.apache.org%3E
http://www.openwall.com/lists/oss-security/2021/03/01/1
https://lists.apache.org/thread.html/[email protected]%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/[email protected]%3Cusers.tomcat.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/03/msg00018.html
https://security.netapp.com/advisory/ntap-20210409-0002/
https://www.debian.org/security/2021/dsa-4891
https://www.oracle.com//security-alerts/cpujul2021.html
https://www.oracle.com/security-alerts/cpuoct2021.html
Source: MITRE
Published: 2021-03-01
Updated: 2022-10-25
Type: CWE-200
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 3.9
Severity: HIGH