Version 9 of ISC BIND, prior to version 9.2.1, contained a denial of service (DoS) attack vulnerability. Various versions of the ISC BIND resolver libraries are vulnerable to a buffer overflow attack.
ISC BIND (Berkeley Internet Name Domain) is an implementation of the DNS (Domain Name System) protocols. BIND includes a DNS server (named) -- which resolves hostnames to IP addresses, a resolver library (routines for applications to use when interfacing with DNS), and various tools. Versions of BIND 9 prior to 9.2.1 have a bug that causes certain requests to the BIND name server to fail an internal consistency check, causing the name server to stop responding to requests. This can be used by a remote attacker to cause a denial of service (DoS) attack against name servers. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2002-0400 to this issue. A buffer overflow vulnerability exists in multiple implementations of DNS resolver libraries. Applications that utilize vulnerable DNS resolver libraries may be affected. A remote attacker who is able to send malicious DNS responses could potentially exploit this vulnerability to execute arbitrary code or cause a denial of service (DoS) attack on a vulnerable system. CentOS Linux does not ship with any applications or libraries that link against the BIND resolver libraries; however, third party code may be affected. (CAN-2002-0651) CentOS Linux Advanced Server shipped with a version of ISC BIND vulnerable to both of these issues. All users of BIND are advised to upgrade to the errata packages containing BIND 9.2.1 which contains backported patches that correct these issues.