Public Date:
1613595: CVE-2018-5740 bind: processing of certain records when "deny-answer-aliases" is in use may trigger an assert leading to a denial of service
A denial of service flaw was discovered in bind versions that include the "deny-answer-aliases" feature. This flaw may allow a remote attacker to trigger an INSIST assert in named leading to termination of the process and a denial of service condition.

Find out more about CVE-2018-5740 from the MITRE CVE dictionary dictionary and NIST NVD.


The "deny-answer-aliases" configuration option is not enabled in default configurations of bind. Upstream states that this option is very rarely used. As such, if customers have not specifically enabled this option in configurations, the risk should be mitigated.

CVSS v3 metrics

CVSS3 Base Score 7.5
CVSS3 Base Metrics CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Impact None
Availability Impact High

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux 7 (bind) RHSA-2018:2570 2018-08-27
Red Hat Enterprise Linux 6 (bind) RHSA-2018:2571 2018-08-27

Affected Packages State

Platform Package State
Red Hat Virtualization 4 bind Not affected
Red Hat Enterprise Linux 8 bind Not affected
Red Hat Enterprise Linux 5 bind97 Will not fix
Red Hat Enterprise Linux 5 bind Not affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.


Red Hat would like to thank ISC for reporting this issue. Upstream acknowledges Tony Finch (University of Cambridge) as the original reporter.


Disabling the "deny-answer-aliases" configuration option should prevent exploitation.

External References

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