PHP before 5.4.42, 5.5.x before 5.5.26, and 5.6.x before 5.6.10 does not ensure that pathnames lack %00 sequences, which might allow remote attackers to read or write to arbitrary files via crafted input to an application that calls (1) a DOMDocument save method or (2) the GD imagepsloadfont function, as demonstrated by a filename\0.html attack that bypasses an intended configuration in which client users may write to only .html files.
https://bugs.php.net/bug.php?id=69719
http://www.securitytracker.com/id/1032709
http://www.securityfocus.com/bid/75244
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
http://www.openwall.com/lists/oss-security/2015/06/16/12
http://www.debian.org/security/2015/dsa-3344
http://rhn.redhat.com/errata/RHSA-2015-1219.html
http://rhn.redhat.com/errata/RHSA-2015-1218.html
http://rhn.redhat.com/errata/RHSA-2015-1187.html
http://rhn.redhat.com/errata/RHSA-2015-1186.html