{"id":"UBUNTU-CVE-2018-8956","details":"ntpd in ntp 4.2.8p10, 4.2.8p11, 4.2.8p12 and 4.2.8p13 allow remote attackers to prevent a broadcast client from synchronizing its clock with a broadcast NTP server via soofed mode 3 and mode 5 packets. The attacker must either be a part of the same broadcast network or control a slave in that broadcast network that can capture certain required packets on the attacker's behalf and send them to the attacker.","modified":"2025-10-24T04:46:58Z","published":"2020-05-06T19:15:00Z","upstream":["CVE-2018-8956"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-8956"},{"type":"REPORT","url":"http://www.ntp.org/"},{"type":"REPORT","url":"https://arxiv.org/abs/2005.01783"},{"type":"REPORT","url":"https://nikhiltripathi.in/NTP_attack.pdf"},{"type":"REPORT","url":"https://tools.ietf.org/html/rfc5905"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-8956"}],"affected":[{"package":{"name":"ntp","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/ntp@1:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1?arch=source&distro=esm-infra-legacy/trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2.6.p5+dfsg-3ubuntu2","1:4.2.6.p5+dfsg-3ubuntu2.14.04.1","1:4.2.6.p5+dfsg-3ubuntu2.14.04.2","1:4.2.6.p5+dfsg-3ubuntu2.14.04.3","1:4.2.6.p5+dfsg-3ubuntu2.14.04.5","1:4.2.6.p5+dfsg-3ubuntu2.14.04.6","1:4.2.6.p5+dfsg-3ubuntu2.14.04.7","1:4.2.6.p5+dfsg-3ubuntu2.14.04.8","1:4.2.6.p5+dfsg-3ubuntu2.14.04.10","1:4.2.6.p5+dfsg-3ubuntu2.14.04.11","1:4.2.6.p5+dfsg-3ubuntu2.14.04.12","1:4.2.6.p5+dfsg-3ubuntu2.14.04.13","1:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1"},{"binary_name":"ntpdate","binary_version":"1:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-8956.json"}},{"package":{"name":"ntp","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ntp@1:4.2.8p4+dfsg-3ubuntu5.10?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2.6.p5+dfsg-3ubuntu8","1:4.2.6.p5+dfsg-3ubuntu8.1","1:4.2.6.p5+dfsg-3ubuntu9","1:4.2.8p4+dfsg-3ubuntu1","1:4.2.8p4+dfsg-3ubuntu2","1:4.2.8p4+dfsg-3ubuntu3","1:4.2.8p4+dfsg-3ubuntu4","1:4.2.8p4+dfsg-3ubuntu5","1:4.2.8p4+dfsg-3ubuntu5.1","1:4.2.8p4+dfsg-3ubuntu5.2","1:4.2.8p4+dfsg-3ubuntu5.3","1:4.2.8p4+dfsg-3ubuntu5.4","1:4.2.8p4+dfsg-3ubuntu5.5","1:4.2.8p4+dfsg-3ubuntu5.6","1:4.2.8p4+dfsg-3ubuntu5.7","1:4.2.8p4+dfsg-3ubuntu5.8","1:4.2.8p4+dfsg-3ubuntu5.9","1:4.2.8p4+dfsg-3ubuntu5.10"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.8p4+dfsg-3ubuntu5.10"},{"binary_name":"ntpdate","binary_version":"1:4.2.8p4+dfsg-3ubuntu5.10"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-8956.json"}},{"package":{"name":"ntp","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/ntp@1:4.2.8p10+dfsg-5ubuntu7.3+esm1?arch=source&distro=esm-apps/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2.8p10+dfsg-5ubuntu3","1:4.2.8p10+dfsg-5ubuntu4","1:4.2.8p10+dfsg-5ubuntu5","1:4.2.8p10+dfsg-5ubuntu6","1:4.2.8p10+dfsg-5ubuntu7","1:4.2.8p10+dfsg-5ubuntu7.1","1:4.2.8p10+dfsg-5ubuntu7.1+esm1","1:4.2.8p10+dfsg-5ubuntu7.1+esm2","1:4.2.8p10+dfsg-5ubuntu7.2","1:4.2.8p10+dfsg-5ubuntu7.2+esm1","1:4.2.8p10+dfsg-5ubuntu7.3","1:4.2.8p10+dfsg-5ubuntu7.3+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.8p10+dfsg-5ubuntu7.3+esm1"},{"binary_name":"ntpdate","binary_version":"1:4.2.8p10+dfsg-5ubuntu7.3+esm1"},{"binary_name":"sntp","binary_version":"1:4.2.8p10+dfsg-5ubuntu7.3+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-8956.json"}},{"package":{"name":"ntp","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/ntp@1:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1?arch=source&distro=esm-apps/focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2.8p12+dfsg-3ubuntu2","1:4.2.8p12+dfsg-3ubuntu3","1:4.2.8p12+dfsg-3ubuntu4","1:4.2.8p12+dfsg-3ubuntu4.20.04.1","1:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1"},{"binary_name":"ntpdate","binary_version":"1:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1"},{"binary_name":"sntp","binary_version":"1:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-8956.json"}},{"package":{"name":"ntp","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ntp@1:4.2.8p15+dfsg-1ubuntu2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2.8p12+dfsg-3ubuntu6","1:4.2.8p15+dfsg-1ubuntu1","1:4.2.8p15+dfsg-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"ntp","binary_version":"1:4.2.8p15+dfsg-1ubuntu2"},{"binary_name":"ntpdate","binary_version":"1:4.2.8p15+dfsg-1ubuntu2"},{"binary_name":"sntp","binary_version":"1:4.2.8p15+dfsg-1ubuntu2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBU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