[dns-operations] BIND Security Advisory

[Keith Mitchell]

[Apologies for any duplicate postings, but this is kind of critical]

See also https://www.isc.org/node/474

BIND Dynamic Update DoS

CVE:	  	CVE-2009-0696 	
CERT:	  	VU#725188 	
Posting date:  	2009-07-28 	
Program Impacted: BIND 	
Versions affected:BIND 9 (all versions)
Severity:  	High 	
Exploitable:  	remotely 	
Summary:  	BIND denial of service (server crash) caused by receipt 	
		of a specific remote dynamic update message.

Description:

Urgent: this exploit is public. Please upgrade immediately.

Receipt of a specially-crafted dynamic update message may cause BIND 9
servers to exit. This vulnerability affects all servers – it is not
limited to those that are configured to allow dynamic updates. Access
controls will not provide an effective workaround.

dns_db_findrdataset() fails when the prerequisite section of the dynamic
update message contains a record of type “ANY” and where at least one
RRset for this FQDN exists on the server.

db.c:659: REQUIRE(type != ((dns_rdatatype_t)dns_rdatatype_any)) failed
exiting (due to assertion failure).

Workarounds:	None.
(Some sites may have firewalls that can be configured with packet
filtering techniques to prevent nsupdate messages from reaching their
nameservers.)

Active exploits:
An active remote exploit is in wide circulation at this time.

Solution:

Upgrade BIND to one of 9.4.3-P3, 9.5.1-P3 or 9.6.1-P1. These versions
can be downloaded from:

    http://ftp.isc.org/isc/bind9/9.6.1-P1/bind-9.6.1-P1.tar.gz
    http://ftp.isc.org/isc/bind9/9.5.1-P3/bind-9.5.1-P3.tar.gz
    http://ftp.isc.org/isc/bind9/9.4.3-P3/bind-9.4.3-P3.tar.gz

Acknowledgement: Matthias Urlichs