The get_icu_disp_value_src_php function in ext/intl/locale/locale_methods.c in PHP before 5.3.29, 5.4.x before 5.4.30, and 5.5.x before 5.5.14 does not properly restrict calls to the ICU uresbund.cpp component, which allows remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact via a locale_get_display_name call with a long first argument.
https://bugzilla.redhat.com/show_bug.cgi?id=1383569
https://bugs.php.net/bug.php?id=67397
http://www.securityfocus.com/bid/68549