Stack-based buffer overflow in the map_uri_to_worker function (native/common/jk_uri_worker_map.c) in mod_jk.so for Apache Tomcat JK Web Server Connector 1.2.19 and 1.2.20, as used in Tomcat 4.1.34 and 5.5.20, allows remote attackers to execute arbitrary code via a long URL that triggers the overflow in a URI worker map routine.