CVE-2013-4854: A specially crafted query can cause BIND to terminate abnormally

A specially crafted query sent to a BIND nameserver can cause it to crash (terminate abnormally).

CVE: CVE-2013-4854

Document version: 2.0

Posting date: 26 July 2013

Program impacted: BIND

Versions affected: Open source: 9.7.0->9.7.7, 9.8.0->9.8.5-P1, 9.9.0->9.9.3-P1, 9.8.6b1 and 9.9.4b1; Subscription: 9.9.3-S1 and 9.9.4-S1b1

Severity: Critical

Exploitable: Remotely

Description:

A specially crafted query that includes malformed rdata can cause named to terminate with an assertion failure while rejecting the malformed query.

BIND 9.6 and BIND 9.6-ESV are unaffected by this problem. Earlier branches of BIND 9 are believed to be unaffected but have not been tested. BIND 10 is also unaffected by this issue.

Please note: All versions of BIND 9.7 are known to be affected, but these branches are beyond their "end of life" (EOL) and no longer receive testing or security fixes from ISC.

Impact:

Authoritative and recursive servers are equally vulnerable. Intentional exploitation of this condition can cause a denial of service in all nameservers running affected versions of BIND 9. Access Control Lists do not provide any protection from malicious clients.

In addition to the named server, applications built using libraries from the affected source distributions may crash with assertion failures triggered in the same fashion.

CVSS Score: 7.8

CVSS Equation: (AV:N/AC:L/Au:N/C:N/I:N/A:C)

For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2&vector=(AV:N/AC:L/Au:N/C:N/I:N/A:C).

Workarounds: No known workarounds at this time.

Active exploits: Crashes have been reported by multiple ISC customers. First observed in the wild on 26 July 2013.

Solution: Upgrade to the patched release most closely related to your current version of BIND.  Open source versions can all be downloaded from https://www.isc.org/downloads/bind. Subscription version customers will be contacted directly by ISC Support regarding delivery.

• BIND 9 version 9.8.5-P2
• BIND 9 version 9.9.3-P2
• BIND 9 version 9.9.3-S1-P1 (Subscription version available via DNSco)

Acknowledgements: ISC would like to thank Maxim Shudrak and the HP Zero Day Initiative for reporting this issue.

Document Revision History:

1.0 Phase One Advance Notification, 18 July 2013
1.1 Phases Two and Three Advance Notification, 26 July 2013
2.0 Notification to public (Phase Four), 26 July 2013

Related Documents:

Spanish Translation: planned
Japanese Translation: https://kb.isc.org/docs/aa-01023
Portuguese Translation: https://kb.isc.org/docs/aa-01021

If you'd like more information on ISC Subscription Support and Advance Security Notifications, please visit https://www.isc.org/support/.

See our BIND 9 Security Vulnerability Matrix for a complete listing of security vulnerabilities and versions affected.

Do you still have questions? Questions regarding this advisory should go to security-officer@isc.org. To report a new issue, please encrypt your message using security-officer@isc.org's PGP key which can be found here: https://www.isc.org/downloads/software-support-policy/openpgp-key/. If you are unable to use encrypted email, you may also report new issues at: https://www.isc.org/community/report-bug/.

Note: ISC patches only currently supported versions. When possible, we indicate EOL versions affected. (For current information on which versions are actively supported, please see https://www.isc.org/downloads/.)

ISC Security Vulnerability Disclosure Policy: Details of our current security advisory policy and practice can be found in the ISC Software Defect and Security Vulnerability Disclosure Policy.

This Knowledgebase article is the complete and official security advisory document.

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