BIND Dynamic Update DoS
时间：2009-07-30 来源：fuleru
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 to a zone for which the server is the master may cause BIND 9 servers to exit. Testing indicates that the attack packet has to be formulated against a zone for which that machine is a master. Launching the attack against slave zones does not trigger the assert.
This vulnerability affects all servers that are masters for one or more zones – 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
Acknowledgment:
Matthias Urlichs for reporting the problem.
Tom Daly for methodical follow-on testing.
Revision History:
2009-07-28 Initial text
2009-07-29 Update to reflect Tom Daly's findings
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