Heap-based buffer overflow in pcrecompile.c in the Perl-Compatible Regular Expression (PCRE) library 7.7 allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a regular expression that begins with an option and contains multiple branches.

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 a birthday attack that uses in-bailiwick referrals to conduct cache poisoning against recursive resolvers, related to insufficient randomness of DNS transaction IDs and source ports, aka "DNS Insufficient Socket Entropy Vulnerability" or "the Kaminsky bug."

Mozilla Firefox before 2.0.0.17 and 3.x before 3.0.2, Thunderbird before 2.0.0.17, and SeaMonkey before 1.1.12 allow remote attackers to bypass cross-site scripting (XSS) protection mechanisms and conduct XSS attacks via byte order mark (BOM) characters that are removed from JavaScript code before execution, aka "Stripped BOM characters bug."