Vulnerability Note VU#198355
ISC BIND 8.2.2-P6 vulnerable to DoS when processing SRV records, aka the "srv bug"
There is a denial-of-service vulnerability in several versions of the Internet Software Consortium's (ISC) BIND software. This vulnerability is referred to by the ISC as the "srv bug" and affects ISC BIND versions 8.2 through 8.2.2-P6.
This vulnerability can cause affected DNS servers running named to go into an infinite loop, thus preventing further name requests to be handled. This can happen if an SRV record (defined in RFC2782) is sent to the vulnerable server.
Microsoft's Windows 2000 Active Directory service makes extensive use of SRV records and is reportedly capable of triggering this bug in the course of normal operations. This is not, however, a vulnerability in Microsoft Active Directory. Any network client capable of sending SRV records to vulnerable name server systems can exercise this vulnerability.
A remote attacker can use malicious SRV records to crash vulnerable BIND servers, resulting in a denial-of-service condition that disables name resolution service.
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To address this vulnerability, the CERT/CC recommends that all users of ISC BIND upgrade to version 8.2.2-P7, which patches both VU#198355 and VU#715973. For information regarding vendor-specific versions of DNS software, please consult the Systems Affected section of this document.
The CERT Coordination Center thanks Mark Andrews, David Conrad, and Paul Vixie of the ISC for developing a solution and assisting in the preparation of this document.
This document was written by Jeffrey S. Havrilla and Jeffrey P. Lanza.
07 Nov 2000
Date First Published:
11 May 2001
Date Last Updated:
25 Jan 2002
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