Integer signedness error in emalloc() function for PHP before 4.3.2 allow remote attackers to cause a denial of service (memory consumption) and possibly execute arbitrary code via negative arguments to functions such as (1) socket_recv, (2) socket_recvfrom, and possibly other functions.
http://marc.info/?l=bugtraq&m=104931415307111&w=2
http://marc.info/?l=bugtraq&m=104878100719467&w=2
http://marc.info/?l=bugtraq&m=104869828526885&w=2
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000691