CVE-2016-9778

An error handling certain queries using the nxdomain-redirect feature could cause a REQUIRE assertion failure in db.c

Description

An error in handling certain queries can cause an assertion failure when a server is using the nxdomain-redirect feature to cover a zone for which it is also providing authoritative service. A vulnerable server could be intentionally stopped by an attacker if it was using a configuration that met the criteria for the vulnerability and if the attacker could cause it to accept a query that possessed the required attributes. Please note: This vulnerability affects the "nxdomain-redirect" feature, which is one of two methods of handling NXDOMAIN redirection, and is only available in certain versions of BIND. Redirection using zones of type "redirect" is not affected by this vulnerability. Affects BIND 9.9.8-S1 -> 9.9.8-S3, 9.9.9-S1 -> 9.9.9-S6, 9.11.0-9.11.0-P1.

Remediation

Solution:

  • Upgrade to the patched release most closely related to your current version of BIND. These can be downloaded from http://www.isc.org/downloads. BIND 9 version 9.11.0-P2 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.9.9-S7

Workaround:

  • Either provide an ordinary (that is: not redirected) NXDOMAIN for non-existent resource records in zones for which authoritative data is served on the same server or use redirect zones instead of the nxdomain-redirect feature.

Category

7.5
CVSS
Severity: High
CVSS 3.0 •
CVSS 2.0 •
EPSS 8.62% Top 10%
Vendor Advisory gentoo.org Vendor Advisory isc.org
Affected: ISC BIND 9
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2016-9778?
CVE-2016-9778 has been scored as a high severity vulnerability.
How to fix CVE-2016-9778?
To fix CVE-2016-9778: Upgrade to the patched release most closely related to your current version of BIND. These can be downloaded from http://www.isc.org/downloads. BIND 9 version 9.11.0-P2 BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. BIND 9.9.9-S7
Is CVE-2016-9778 being actively exploited in the wild?
It is possible that CVE-2016-9778 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~9% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2016-9778?
CVE-2016-9778 affects ISC BIND 9.
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