CVE-2023-46589: Apache Tomcat: HTTP request smuggling via malformed trailer headers

[Mark Thomas <markt () apache org>]

Severity: important

Affected versions:

- Apache Tomcat 11.0.0-M1 through 11.0.0-M10
- Apache Tomcat 10.1.0-M1 through 10.1.15
- Apache Tomcat 9.0.0-M1 through 9.0.82
- Apache Tomcat 8.5.0 through 8.5.95

Description:

Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 
11.0.0-M1 through 11.0.0-M10, from 10.1.0-M1 through 10.1.15, from 
9.0.0-M1 through 9.0.82 and from 8.5.0 through 8.5.95 did not correctly 
parse HTTP trailer headers. A trailer header that exceeded the header 
size limit could cause Tomcat to treat a single
request as multiple requests leading to the possibility of request
smuggling when behind a reverse proxy.

Users are recommended to upgrade to version 11.0.0-M11 onwards, 10.1.16 
onwards, 9.0.83 onwards or 8.5.96 onwards, which fix the issue.

Credit:

Norihito Aimoto (OSSTech Corporation)  (finder)

References:

https://lists.apache.org/thread/0rqq6ktozqc42ro8hhxdmmdjm1k1tpxr
https://tomcat.apache.org/
https://www.cve.org/CVERecord?id=CVE-2023-46589