The phpinfo implementation in ext/standard/info.c in PHP before 5.4.30 and 5.5.x before 5.5.14 does not ensure use of the string data type for the PHP_AUTH_PW, PHP_AUTH_TYPE, PHP_AUTH_USER, and PHP_SELF variables, which might allow context-dependent attackers to obtain sensitive information from process memory by using the integer data type with crafted values, related to a "type confusion" vulnerability, as demonstrated by reading a private SSL key in an Apache HTTP Server web-hosting environment with mod_ssl and a PHP 5.3.x mod_php.
https://bugs.php.net/bug.php?id=67498
http://www.php.net/ChangeLog-5.php
http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html
http://www.debian.org/security/2014/dsa-2974
http://www-01.ibm.com/support/docview.wss?uid=swg21683486
http://twitter.com/mikispag/statuses/485713462258302976
http://rhn.redhat.com/errata/RHSA-2014-1766.html
http://rhn.redhat.com/errata/RHSA-2014-1765.html
http://lists.opensuse.org/opensuse-updates/2014-09/msg00046.html
http://lists.opensuse.org/opensuse-updates/2014-07/msg00035.html