{"id":"UBUNTU-CVE-2018-5733","details":"A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -\u003e 4.1-ESV-R15, 4.2.0 -\u003e 4.2.8, 4.3.0 -\u003e 4.3.6, 4.4.0.","modified":"2026-02-04T02:54:53.080260Z","published":"2018-03-01T00:00:00Z","related":["USN-3586-1","USN-3586-2"],"upstream":["CVE-2018-5733"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-5733"},{"type":"REPORT","url":"https://kb.isc.org/article/AA-01567/75/CVE-2018-5733"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3586-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-3586-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-5733"}],"affected":[{"package":{"name":"isc-dhcp","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/isc-dhcp@4.2.4-7ubuntu12.12?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.4-7ubuntu12.12"}]}],"versions":["4.2.4-7ubuntu8","4.2.4-7ubuntu9","4.2.4-7ubuntu10","4.2.4-7ubuntu11","4.2.4-7ubuntu12","4.2.4-7ubuntu12.1","4.2.4-7ubuntu12.2","4.2.4-7ubuntu12.3","4.2.4-7ubuntu12.4","4.2.4-7ubuntu12.5","4.2.4-7ubuntu12.6","4.2.4-7ubuntu12.7","4.2.4-7ubuntu12.8","4.2.4-7ubuntu12.9","4.2.4-7ubuntu12.10"],"ecosystem_specific":{"binaries":[{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-client"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-client-noddns"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-common"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-dev"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-relay"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-server"},{"binary_version":"4.2.4-7ubuntu12.12","binary_name":"isc-dhcp-server-ldap"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-5733.json"}},{"package":{"name":"isc-dhcp","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/isc-dhcp@4.3.3-5ubuntu12.9?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.3.3-5ubuntu12.9"}]}],"versions":["4.3.1-5ubuntu3","4.3.1-5ubuntu4","4.3.1-5ubuntu5","4.3.3-5ubuntu1","4.3.3-5ubuntu2","4.3.3-5ubuntu4","4.3.3-5ubuntu5","4.3.3-5ubuntu7","4.3.3-5ubuntu8","4.3.3-5ubuntu9","4.3.3-5ubuntu10","4.3.3-5ubuntu11","4.3.3-5ubuntu12","4.3.3-5ubuntu12.1","4.3.3-5ubuntu12.3","4.3.3-5ubuntu12.4","4.3.3-5ubuntu12.6","4.3.3-5ubuntu12.7"],"ecosystem_specific":{"binaries":[{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-client"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-client-ddns"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-common"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-dev"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-relay"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-server"},{"binary_version":"4.3.3-5ubuntu12.9","binary_name":"isc-dhcp-server-ldap"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-5733.json"}},{"package":{"name":"isc-dhcp","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/isc-dhcp@4.3.5-3ubuntu5?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.3.5-3ubuntu5"}]}],"versions":["4.3.5-3ubuntu2","4.3.5-3ubuntu3","4.3.5-3ubuntu4"],"ecosystem_specific":{"binaries":[{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-client"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-client-ddns"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-common"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-dev"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-relay"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-server"},{"binary_version":"4.3.5-3ubuntu5","binary_name":"isc-dhcp-server-ldap"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-5733.json"}}],"schema_version":"1.7.3","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":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}