CVE-2018-5743

Description

By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers. Unfortunately, the code which was intended to limit the number of simultaneous connections contained an error which could be exploited to grow the number of simultaneous connections beyond this limit. Versions affected: BIND 9.9.0 -> 9.10.8-P1, 9.11.0 -> 9.11.6, 9.12.0 -> 9.12.4, 9.14.0. BIND 9 Supported Preview Edition versions 9.9.3-S1 -> 9.11.5-S3, and 9.11.5-S5. Versions 9.13.0 -> 9.13.7 of the 9.13 development branch are also affected. Versions prior to BIND 9.9.0 have not been evaluated for vulnerability to CVE-2018-5743.

How to fix CVE-2018-5743

To remediate CVE-2018-5743, upgrade the affected package to a fixed version below.

• —upgrade to 9.14.1-r0 or later
• —upgrade to 1:9.11.5.P4+dfsg-4 or later
• —upgrade to 1:9.9.5.dfsg-9+deb8u18 or later
• —upgrade to 1:9.10.3.dfsg.P4-12.3+deb9u5 or later

Is CVE-2018-5743 being exploited?

Moderate — EPSS is 5.7%. Track this CVE but it's not at the top of the prioritisation list.

Affected packages (4)

• from 0, < 9.14.1-r0
• from 0, < 1:9.11.5.P4+dfsg-4
• from 0, < 1:9.9.5.dfsg-9+deb8u18
• from 0, < 1:9.10.3.dfsg.P4-12.3+deb9u5

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2018-5743
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2018-5743