{"id":"UBUNTU-CVE-2023-51765","details":"sendmail through 8.17.2 allows SMTP smuggling in certain configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because sendmail supports \u003cLF\u003e.\u003cCR\u003e\u003cLF\u003e but some other popular e-mail servers do not. This is resolved in 8.18 and later versions with 'o' in srv_features.","modified":"2026-04-22T14:15:49.613762Z","published":"2023-12-24T06:15:00Z","upstream":["CVE-2023-51765"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-51765"},{"type":"REPORT","url":"https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2023/12/21/6"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2023/12/26/5"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-51765"}],"affected":[{"package":{"name":"sendmail","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/sendmail@8.14.4-4.1ubuntu1.1?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.14.4-2.1ubuntu4","8.14.4-2.1ubuntu5","8.14.4-4.1ubuntu1","8.14.4-4.1ubuntu1.1"],"ecosystem_specific":{"binaries":[{"binary_version":"8.14.4-4.1ubuntu1.1","binary_name":"libmilter1.0.1"},{"binary_name":"rmail","binary_version":"8.14.4-4.1ubuntu1.1"},{"binary_name":"sendmail","binary_version":"8.14.4-4.1ubuntu1.1"},{"binary_name":"sendmail-base","binary_version":"8.14.4-4.1ubuntu1.1"},{"binary_name":"sendmail-bin","binary_version":"8.14.4-4.1ubuntu1.1"},{"binary_name":"sendmail-cf","binary_version":"8.14.4-4.1ubuntu1.1"},{"binary_version":"8.14.4-4.1ubuntu1.1","binary_name":"sensible-mda"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-51765.json"}},{"package":{"name":"sendmail","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/sendmail@8.15.2-3?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.14.9-4","8.15.2-2","8.15.2-3"],"ecosystem_specific":{"binaries":[{"binary_name":"libmilter1.0.1","binary_version":"8.15.2-3"},{"binary_name":"rmail","binary_version":"8.15.2-3"},{"binary_name":"sendmail","binary_version":"8.15.2-3"},{"binary_name":"sendmail-base","binary_version":"8.15.2-3"},{"binary_name":"sendmail-bin","binary_version":"8.15.2-3"},{"binary_name":"sendmail-cf","binary_version":"8.15.2-3"},{"binary_name":"sensible-mda","binary_version":"8.15.2-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-51765.json"}},{"package":{"name":"sendmail","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/sendmail@8.15.2-10?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.15.2-8ubuntu1","8.15.2-9ubuntu1","8.15.2-10"],"ecosystem_specific":{"binaries":[{"binary_version":"8.15.2-10","binary_name":"libmilter1.0.1"},{"binary_name":"rmail","binary_version":"8.15.2-10"},{"binary_name":"sendmail","binary_version":"8.15.2-10"},{"binary_name":"sendmail-base","binary_version":"8.15.2-10"},{"binary_version":"8.15.2-10","binary_name":"sendmail-bin"},{"binary_name":"sendmail-cf","binary_version":"8.15.2-10"},{"binary_name":"sensible-mda","binary_version":"8.15.2-10"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-51765.json"}},{"package":{"name":"sendmail","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/sendmail@8.15.2-18?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.15.2-13","8.15.2-17ubuntu1","8.15.2-18"],"ecosystem_specific":{"binaries":[{"binary_name":"libmilter1.0.1","binary_version":"8.15.2-18"},{"binary_name":"rmail","binary_version":"8.15.2-18"},{"binary_version":"8.15.2-18","binary_name":"sendmail"},{"binary_name":"sendmail-base","binary_version":"8.15.2-18"},{"binary_name":"sendmail-bin","binary_version":"8.15.2-18"},{"binary_name":"sendmail-cf","binary_version":"8.15.2-18"},{"binary_version":"8.15.2-18","binary_name":"sensible-mda"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-51765.json"}},{"package":{"name":"sendmail","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/sendmail@8.15.2-22ubuntu3?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.15.2-22ubuntu2","8.15.2-22ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_name":"libmilter1.0.1","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"rmail","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"sendmail","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"sendmail-base","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"sendmail-bin","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"sendmail-cf","binary_version":"8.15.2-22ubuntu3"},{"binary_name":"sensible-mda","binary_version":"8.15.2-22ubuntu3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-51765.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:L/A:N"},{"type":"Ubuntu","score":"medium"}]}