The DNS protocol, as implemented in (1) BIND 8 and 9 before 9.5.0-P1, 9.4.2-P1, and 9.3.5-P1; (2) Microsoft DNS in Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP1 and SP2; and other implementations allow remote attackers to spoof DNS traffic via certain cache poisoning techniques against recursive resolvers, related to insufficient randomness of DNS transaction IDs and source ports, aka "DNS Insufficient Socket Entropy Vulnerability."

ISC BIND 9 through 9.5.0a5 uses a weak random number generator during generation of DNS query ids when answering resolver questions or sending NOTIFY messages to slave name servers, which makes it easier for remote attackers to guess the next query id and perform DNS cache poisoning.

Microsoft Windows NAT Helper Components (ipnathlp.dll) on Windows XP SP2, when Internet Connection Sharing is enabled, allows remote attackers to cause a denial of service (svchost.exe crash) via a malformed DNS query, which results in a null pointer dereference.

Buffer overflow in transaction signature (TSIG) handling code in BIND 8 allows remote attackers to gain root privileges.

Inverse query buffer overflow in BIND 4.9 and BIND 8 Releases.

A DNS server allows zone transfers.