Apache HTTP Server Numeric Errors Vulnerability - CVE-2011-3607
Integer overflow in the ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21 when the mod_setenvif module is enabled allows local users to gain privileges via a .htaccess file with a crafted SetEnvIf directive in conjunction with a crafted HTTP request header leading to a heap-based buffer overflow.