Apache Tomcat 5.5.0 and 4.1.0 through 4.1.31 allows remote attackers to bypass an IP address restriction and obtain sensitive information via a request that is processed concurrently with another request but in a different thread, leading to an instance-variable overwrite associated with a "synchronization problem" and lack of thread safety, and related to RemoteFilterValve, RemoteAddrValve, and RemoteHostValve.
https://issues.apache.org/bugzilla/show_bug.cgi?id=25835
https://exchange.xforce.ibmcloud.com/vulnerabilities/45791
http://www.vupen.com/english/advisories/2009/1818
http://www.vupen.com/english/advisories/2008/2800
http://www.vupen.com/english/advisories/2008/2793
http://www.securitytracker.com/id?1021039
http://www.securityfocus.com/bid/31698
http://www.securityfocus.com/archive/1/497220/100/0/threaded
http://www.nec.co.jp/security-info/secinfo/nv09-006.html
http://www.fujitsu.com/global/support/software/security/products-f/interstage-200806e.html
http://tomcat.apache.org/security-5.html
http://tomcat.apache.org/security-4.html
http://securityreason.com/securityalert/4396
http://secunia.com/advisories/35684
http://secunia.com/advisories/32398
http://secunia.com/advisories/32234
http://secunia.com/advisories/32213
http://lists.opensuse.org/opensuse-security-announce/2008-10/msg00012.html