An issue with modjk 1.2.26, and possibly older versions, allows one user to see another user's information due to missing logic where faulty clients set Content-Length without providing data, or if a user submits too many times very fast.

The relevant changelog entry in modjk 1.2.27 that corrects the issue is:

"AJP13: Always send initial POST packet even if the client disconnected after sending request but before providing POST data. In that case or in case the client broke the connection in a middle of read send an zero size packet informing container about broken client connection. (mturk)"

from http://tomcat.apache.org/connectors-doc/miscellaneous/changelog.html