PHP 5.2.4 and earlier allows context-dependent attackers to cause a denial of service (application crash) via (1) a long string in the out_charset parameter to the iconv function; or a long string in the charset parameter to the (2) iconv_mime_decode_headers, (3) iconv_mime_decode, or (4) iconv_strlen function. NOTE: this might not be a vulnerability in most web server environments that support multiple threads, unless these issues can be demonstrated for code execution.
https://issues.rpath.com/browse/RPL-1943
http://www.securityfocus.com/archive/1/491693/100/0/threaded
http://www.securityfocus.com/archive/1/478730/100/0/threaded
http://www.gentoo.org/security/en/glsa/glsa-200710-02.xml
http://wiki.rpath.com/wiki/Advisories:rPSA-2007-0242
http://securityreason.com/securityalert/3122
http://secunia.com/advisories/30040
http://secunia.com/advisories/28658
http://secunia.com/advisories/27659
http://secunia.com/advisories/27102
http://lists.opensuse.org/opensuse-security-announce/2008-01/msg00006.html