Exposure of Sensitive Information to an Unauthorized Actor
A regression in the fix for bug 66512 in Apache Tomcat, 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. This vulnerability affects Apache Tomcat versions 11.0.0-M5, 10.1.8, 9.0.74 and 8.5.88.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.