The register_globals emulation in phpMyAdmin 2.7.0 rc1 allows remote attackers to exploit other vulnerabilities in phpMyAdmin by modifying the import_blacklist variable in grab_globals.php, which can then be used to overwrite other variables.
http://www.vupen.com/english/advisories/2005/2792
http://www.securityfocus.com/bid/15761
http://www.securityfocus.com/archive/1/423142/100/0/threaded
http://www.securityfocus.com/archive/1/418834/100/0/threaded
http://www.phpmyadmin.net/home_page/security.php?issue=PMASA-2005-9
http://www.phpmyadmin.net/home_page/downloads.php?relnotes=0
http://www.hardened-php.net/advisory_252005.110.html
http://www.gentoo.org/security/en/glsa/glsa-200512-03.xml
http://securityreason.com/securityalert/237
http://secunia.com/advisories/18618