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 message would 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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-34981
• https://lists.apache.org/thread/j1ksjh9m9gx1q60rtk1sbzmxhvj5h5qz
• https://bz.apache.org/bugzilla/show_bug.cgi?id=66512
• https://bz.apache.org/bugzilla/show_bug.cgi?id=66591
• https://tomcat.apache.org/security-10.html
• https://tomcat.apache.org/security-11.html
• https://tomcat.apache.org/security-8.html
• https://tomcat.apache.org/security-9.html
• apache/tomcat@2214c80
• apache/tomcat@2f0ca23
• apache/tomcat@739c738
• apache/tomcat@f0742f4
• https://security.netapp.com/advisory/ntap-20230714-0003