{"id":"UBUNTU-CVE-2023-2911","details":"If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow. This issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15, 9.16.33-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.","modified":"2026-04-22T16:40:11.161278Z","published":"2023-06-21T00:00:00Z","related":["USN-6183-1"],"upstream":["CVE-2023-2911"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-2911"},{"type":"REPORT","url":"https://kb.isc.org/v1/docs/cve-2023-2911"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6183-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-2911"}],"affected":[{"package":{"name":"bind9","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/bind9@1:9.16.1-0ubuntu2.15?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.16.1-0ubuntu2.15"}]}],"versions":["1:9.11.5.P4+dfsg-5.1ubuntu2","1:9.11.5.P4+dfsg-5.1ubuntu3","1:9.11.5.P4+dfsg-5.1ubuntu4","1:9.11.5.P4+dfsg-5.1ubuntu5","1:9.11.14+dfsg-1ubuntu1","1:9.11.14+dfsg-3ubuntu1","1:9.16.0-1ubuntu3","1:9.16.0-1ubuntu4","1:9.16.0-1ubuntu5","1:9.16.1-0ubuntu1","1:9.16.1-0ubuntu2","1:9.16.1-0ubuntu2.1","1:9.16.1-0ubuntu2.2","1:9.16.1-0ubuntu2.3","1:9.16.1-0ubuntu2.4","1:9.16.1-0ubuntu2.6","1:9.16.1-0ubuntu2.7","1:9.16.1-0ubuntu2.8","1:9.16.1-0ubuntu2.9","1:9.16.1-0ubuntu2.10","1:9.16.1-0ubuntu2.11","1:9.16.1-0ubuntu2.12","1:9.16.1-0ubuntu2.14"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"bind9","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"bind9-dnsutils","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"bind9-host","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"bind9-libs","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"bind9-utils","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"bind9utils","binary_version":"1:9.16.1-0ubuntu2.15"},{"binary_name":"dnsutils","binary_version":"1:9.16.1-0ubuntu2.15"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-2911.json"}},{"package":{"name":"bind9","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/bind9@1:9.18.12-0ubuntu0.22.04.2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:9.18.12-0ubuntu0.22.04.2"}]}],"versions":["1:9.16.15-1ubuntu1","1:9.16.15-1ubuntu2","1:9.16.15-1ubuntu3","1:9.18.0-2ubuntu1","1:9.18.0-2ubuntu2","1:9.18.0-2ubuntu3","1:9.18.1-1ubuntu1","1:9.18.1-1ubuntu1.1","1:9.18.1-1ubuntu1.2","1:9.18.1-1ubuntu1.3","1:9.18.12-0ubuntu0.22.04.1"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"bind9","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"bind9-dnsutils","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"bind9-host","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"bind9-libs","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"bind9-utils","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"bind9utils","binary_version":"1:9.18.12-0ubuntu0.22.04.2"},{"binary_name":"dnsutils","binary_version":"1:9.18.12-0ubuntu0.22.04.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-2911.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}