{"id":"UBUNTU-CVE-2018-5738","details":"Change #4777 (introduced in October 2017) introduced an unforeseen issue in releases which were issued after that date, affecting which clients are permitted to make recursive queries to a BIND nameserver. The intended (and documented) behavior is that if an operator has not specified a value for the \"allow-recursion\" setting, it SHOULD default to one of the following: none, if \"recursion no;\" is set in named.conf; a value inherited from the \"allow-query-cache\" or \"allow-query\" settings IF \"recursion yes;\" (the default for that setting) AND match lists are explicitly set for \"allow-query-cache\" or \"allow-query\" (see the BIND9 Administrative Reference Manual section 6.2 for more details); or the intended default of \"allow-recursion {localhost; localnets;};\" if \"recursion yes;\" is in effect and no values are explicitly set for \"allow-query-cache\" or \"allow-query\". However, because of the regression introduced by change #4777, it is possible when \"recursion yes;\" is in effect and no match list values are provided for \"allow-query-cache\" or \"allow-query\" for the setting of \"allow-recursion\" to inherit a setting of all hosts from the \"allow-query\" setting default, improperly permitting recursion to all clients. Affects BIND 9.9.12, 9.10.7, 9.11.3, 9.12.0-\u003e9.12.1-P2, the development release 9.13.0, and also releases 9.9.12-S1, 9.10.7-S1, 9.11.3-S1, and 9.11.3-S2 from BIND 9 Supported Preview Edition.","modified":"2026-04-22T13:14:00.088981Z","published":"2018-06-12T00:00:00Z","related":["USN-3683-1"],"upstream":["CVE-2018-5738"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-5738"},{"type":"REPORT","url":"https://kb.isc.org/article/AA-01616/0/CVE-2018-5738"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3683-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-5738"}],"affected":[{"package":{"name":"bind9","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/bind9@1:9.11.3+dfsg-1ubuntu1.1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.11.3+dfsg-1ubuntu1.1"}]}],"versions":["1:9.10.3.dfsg.P4-12.6ubuntu1","1:9.11.2.P1-1ubuntu2","1:9.11.2.P1-1ubuntu3","1:9.11.2.P1-1ubuntu4","1:9.11.2.P1-1ubuntu5","1:9.11.3+dfsg-1ubuntu1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"bind9","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"bind9-host","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"bind9utils","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"dnsutils","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libbind9-160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_version":"1:9.11.3+dfsg-1ubuntu1.1","binary_name":"libdns-export1100"},{"binary_name":"libdns1100","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libirs-export160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libirs160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_version":"1:9.11.3+dfsg-1ubuntu1.1","binary_name":"libisc-export169"},{"binary_name":"libisc169","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libisccc-export160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libisccc160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libisccfg-export160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"libisccfg160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"},{"binary_name":"liblwres160","binary_version":"1:9.11.3+dfsg-1ubuntu1.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-5738.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}