CVE-2014-8500: A Defect in Delegation Handling Can Be Exploited to Crash BIND
- Updated on 18 Apr 2016
- 3 minutes to read
Failure to place limits on delegation chaining can allow an attacker to crash BIND or cause memory exhaustion.
08 December 2014
9.0.x -> 9.8.x, 9.9.0 -> 9.9.6, 9.10.0 -> 9.10.1
By making use of maliciously-constructed zones or a rogue server, an attacker can exploit an oversight in the code BIND 9 uses to follow delegations in the Domain Name Service, causing BIND to issue unlimited queries in an attempt to follow the delegation. This can lead to resource exhaustion and denial of service (up to and including termination of the named server process.)
All recursive resolvers are affected. Authoritative servers can be affected if an attacker can control a delegation traversed by the authoritative server in servicing the zone.
CVSS Score: 7.8
CVSS Vector: (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&version=2&vector=(AV:N/AC:L/Au:N/C:N/I:N/A:C)
No workarounds exist. Vulnerable versions of BIND 9 should be upgraded.
No known active exploits.
Solution: Upgrade to the patched release most closely related to your current version of BIND. Patched builds of currently supported branches of BIND (9.9 and 9.10) can be downloaded via http://www.isc.org/downloads
- BIND 9 version 9.9.6-P1
- BIND 9 version 9.10.1-P1
Regarding older versions:
- BIND 9.6-ESV and BIND 9.8 have been officially designated "end of life" (EOL) and no longer receive support. All organizations running EOL branches should be planning transition to currently supported branches. However, due to the severity of this particular issue, source code diffs which can be applied to BIND 9.8 and BIND 9.6-ESV will be made available on request to firstname.lastname@example.org.
Acknowledgements: ISC would like to thank Florian Maury (ANSSI) for discovering and reporting this vulnerability.
Document Revision History:
1.0 Advance Notification: 20 November 2014 2.0 Public Disclosure: 08 December 2014
See our BIND9 Security Vulnerability Matrix at https://kb.isc.org/article/AA-00913 for a complete listing of Security Vulnerabilities and versions affected.
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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 http://www.isc.org/downloads/).
ISC Security Vulnerability Disclosure Policy: Details of our current security advisory policy and practice can be found here:https://kb.isc.org/article/AA-00861/164/ISC-Software-Defect-and-Security-Vulnerability-Disclosure-Policy.htmlThis Knowledge Base article https://kb.isc.org/article/AA-01216 is the complete and official security advisory document.
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