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CVE-2016-1286: A problem parsing resource record signatures for DNAME resource records can lead to an assertion failure in resolver.c or db.c
Author: Michael McNally Reference Number: AA-01353 Views: 74363 Created: 2016-03-09 18:00 Last Updated: 2016-04-18 23:34 0 Rating/ Voters

Document Version:          
Posting date: 
09 March 2016
Program Impacted: 
Versions affected: 
9.0.0 -> 9.8.8, 9.9.0 -> 9.9.8-P3, 9.9.3-S1 -> 9.9.8-S5,  9.10.0 -> 9.10.3-P3


An error when parsing signature records for DNAME records having specific properties can lead to named exiting due to an assertion failure in resolver.c or db.c.


An attacker able to cause a server to make a query deliberately chosen to generate a response containing a signature record which would exercise this vulnerability can cause named to stop execution with an assertion failure, resulting in denial of service to clients.  Recursive resolvers are at the highest risk of vulnerability to this attack but authoritative-only servers may be also be vulnerable if the attacker can control the answers for records requested when the authoritative server is performing service on zones (e.g. a slave server doing SOA queries.)  Servers may be affected even if they are not performing validation or have DNSSEC disabled entirely as long as they receive a response containing offending signature records.  Disabling DNSSEC does not provide protection against this vulnerability.

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:


None known.

Active exploits:

No known active exploits.

Solution:  Upgrade to the patched release most closely related to your current version of BIND:

  • BIND 9 version 9.9.8-P4
  • BIND 9 version 9.10.3-P4

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-S6

Document Revision History:

1.0 Advance Notification 02 March 2016
1.1 "Versions affected" and "Solution" text expanded to cover BIND 9 Supported Preview Edition; "Versions affected" and "Impact" text expanded to cover all old versions. 07 March 2016
2.0 Public Disclosure.  09 March 2016

Related Documents:

See our BIND9 Security Vulnerability Matrix at for a complete listing of Security Vulnerabilities and versions affected.

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