Apache HttpClient 4.x before 4.1.1 in Apache HttpComponents, when used with an authenticating proxy server, sends the Proxy-Authorization header to the origin server, which allows remote web servers to obtain sensitive information by logging this header.
lists.fedoraproject.org/pipermail/package-announce/2011-June/061440.html
marc.info/?l=httpclient-users&m=129853896315461&w=2
marc.info/?l=httpclient-users&m=129856318011586&w=2
marc.info/?l=httpclient-users&m=129857589129183&w=2
marc.info/?l=httpclient-users&m=129858274406594&w=2
marc.info/?l=httpclient-users&m=129858299106950&w=2
openwall.com/lists/oss-security/2011/04/07/7
openwall.com/lists/oss-security/2011/04/08/1
securityreason.com/securityalert/8298
www.apache.org/dist/httpcomponents/httpclient/RELEASE_NOTES-4.1.x.txt
www.kb.cert.org/vuls/id/153049
www.securityfocus.com/bid/46974
bugzilla.redhat.com/show_bug.cgi?id=709531
issues.apache.org/jira/browse/HTTPCLIENT-1061