The Bonjour functionality in mDNSResponder, iChat 3.1.6, and InstantMessage framework 428 in Apple Mac OS X 10.4.8 does not check for duplicate entries when adding newly discovered available contacts, which allows remote attackers to cause a denial of service (disrupted communication) via a flood of duplicate _presence._tcp mDNS queries.

Multiple buffer overflows in mDNSResponder before 625.41.2 allow remote attackers to read or write to out-of-bounds memory locations via vectors involving the (1) GetValueForIPv4Addr, (2) GetValueForMACAddr, (3) rfc3110_import, or (4) CopyNSEC3ResourceRecord function.

The handle_regservice_request function in mDNSResponder before 625.41.2 allows remote attackers to execute arbitrary code or cause a denial of service (NULL pointer dereference) via unspecified vectors.