{"id":"UBUNTU-CVE-2021-37845","details":"An issue was discovered in Citadel through webcit-932. A meddler-in-the-middle attacker can fixate their own session during the cleartext phase before a STARTTLS command (a violation of \"The STARTTLS command is only valid in non-authenticated state.\" in RFC2595). This potentially allows an attacker to cause a victim's e-mail messages to be stored into an attacker's IMAP mailbox, but depends on details of the victim's client behavior.","modified":"2025-10-24T04:50:27Z","published":"2023-05-29T19:15:00Z","upstream":["CVE-2021-37845"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-37845"},{"type":"REPORT","url":"https://uncensored.citadel.org/readfwd?go=Citadel"},{"type":"REPORT","url":"https://nostarttls.secvuln.info/"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-37845"}],"affected":[{"package":{"name":"citadel","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/citadel@9.01-1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["9.01-1"],"ecosystem_specific":{"binaries":[{"binary_name":"citadel-mta","binary_version":"9.01-1"},{"binary_name":"citadel-server","binary_version":"9.01-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-37845.json"}},{"package":{"name":"citadel","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/citadel@917-2?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["911-1","917-2"],"ecosystem_specific":{"binaries":[{"binary_name":"citadel-server","binary_version":"917-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-37845.json"}},{"package":{"name":"citadel","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/citadel@917-4?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["917-3","917-4"],"ecosystem_specific":{"binaries":[{"binary_name":"citadel-server","binary_version":"917-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-37845.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}