CVE-2015-8461: A race condition when handling socket errors can lead to an assertion failure in resolver.c
Document version: 2.0
Posting date: 15 December 2015
Program impacted: BIND
Versions affected: 9.9.8 -> 9.9.8-P1, 9.9.8-S1 -> 9.9.8-S2, 9.10.3 -> 9.10.3-P1
Beginning with the September 2015 maintenance releases 9.9.8 and 9.10.3, an error was introduced into BIND 9 which can cause a server to exit after encountering an INSIST assertion failure in resolver.c.
An uncommonly occurring condition can cause affected servers to exit with an INSIST failure depending on the outcome of a race condition in resolver.c. While difficult to exploit reliably, a malicious party could, through deliberate behavior, significantly increase the probability of encountering the triggering condition, resulting in denial of service to clients if successful.
CVSS Score: 5.4
CVSS Vector: (AV:N/AC:H/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: https://nvd.nist.gov/cvss.cfm?calculator&version=2&vector=(AV:N/AC:H/Au:N/C:N/I:N/A:C).
Active exploits: None known.
Solution: Upgrade to the patched release most closely related to your current version of BIND. Public open-source branches can be downloaded from https://www.isc.org/downloads.
- BIND 9 version 9.9.8-P2
- BIND 9 version 9.10.3-P2
BIND 9 Supported Preview edition is a feature preview version of BIND provided exclusively to eligible ISC Support customers.
- BIND 9 version 9.9.8-S3
Acknowledgements: ISC would like to thank John O'Brien of the University of Pennsylvania for discovering this issue.
Document Revision History:
1.0 Advance Notification. 8 December 2015 2.0 Public Disclosure. 15 December 2015
Related Documents: See our BIND 9 Security Vulnerability Matrix 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 https://www.isc.org/downloads/).
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