PHP 4.x up to 4.4.4 and PHP 5 up to 5.1.6 allows local users to bypass certain Apache HTTP Server httpd.conf options, such as safe_mode and open_basedir, via the ini_restore function, which resets the values to their php.ini (Master Value) defaults.
https://exchange.xforce.ibmcloud.com/vulnerabilities/28853
http://www.vupen.com/english/advisories/2007/2374
http://www.vupen.com/english/advisories/2007/1991
http://www.ubuntu.com/usn/usn-362-1
http://www.turbolinux.com/security/2006/TLSA-2006-38.txt
http://www.securityfocus.com/archive/1/448953/100/0/threaded
http://www.securityfocus.com/archive/1/445882/100/0/threaded
http://www.securityfocus.com/archive/1/445712/100/0/threaded
http://www.mandriva.com/security/advisories?name=MDKSA-2006:185
http://securityreason.com/securityalert/1519
http://secunia.com/advisories/25850
http://secunia.com/advisories/25423
http://secunia.com/advisories/22424
http://secunia.com/advisories/22338
http://secunia.com/advisories/22331
http://secunia.com/advisories/22282
http://lists.suse.com/archive/suse-security-announce/2006-Oct/0002.html
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c01086137
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c01056506