The _expand_quoted_text function in libs/Smarty_Compiler.class.php in Smarty 2.6.20 before r2797 allows remote attackers to execute arbitrary PHP code via vectors related to templates and (1) a dollar-sign character, aka "php executed in templates;" and (2) a double quoted literal string, aka a "function injection security hole." NOTE: each vector affects slightly different SVN revisions.
https://exchange.xforce.ibmcloud.com/vulnerabilities/46031
https://bugs.gentoo.org/attachment.cgi?id=169804&action=view
http://www.securityfocus.com/bid/31862
http://www.openwall.com/lists/oss-security/2008/10/25/2
http://www.debian.org/security/2008/dsa-1691
http://smarty-php.googlecode.com/svn/trunk/NEWS
http://securityvulns.ru/Udocument746.html
http://secunia.com/advisories/32329
http://code.google.com/p/smarty-php/source/detail?r=2797&path=/trunk/libs/Smarty_Compiler.class.php
http://code.google.com/p/smarty-php/source/detail?r=2784&path=/trunk/libs/Smarty_Compiler.class.php