CVE-2018-5740

Publication date 9 August 2018

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

"deny-answer-aliases" is a little-used feature intended to help recursive server operators protect end users against DNS rebinding attacks, a potential method of circumventing the security model used by client browsers. However, a defect in this feature makes it easy, when the feature is in use, to experience an assertion failure in name.c. Affects BIND 9.7.0->9.8.8, 9.9.0->9.9.13, 9.10.0->9.10.8, 9.11.0->9.11.4, 9.12.0->9.12.2, 9.13.0->9.13.2.

Mitigation

Disable use of "deny-answer-aliases" feature

Status

Package Ubuntu Release Status
bind9 18.04 LTS bionic
Fixed 1:9.11.3+dfsg-1ubuntu1.2
16.04 LTS xenial
Fixed 1:9.10.3.dfsg.P4-8ubuntu1.11
14.04 LTS trusty
Fixed 1:9.9.5.dfsg-3ubuntu0.18

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

Other references