{"id":"UBUNTU-CVE-2021-20247","details":"A flaw was found in mbsync before v1.3.5 and v1.4.1. Validations of the mailbox names returned by IMAP LIST/LSUB do not occur allowing a malicious or compromised server to use specially crafted mailbox names containing '..' path components to access data outside the designated mailbox on the opposite end of the synchronization channel. The highest threat from this vulnerability is to data confidentiality and integrity.","modified":"2026-05-20T16:06:25.918951210Z","published":"2021-02-23T19:15:00Z","upstream":["CVE-2021-20247"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-20247"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2021/02/22/1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-20247"}],"affected":[{"package":{"name":"isync","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.1.2-1","binary_name":"isync"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.1-2","1.3.0-1","1.3.0-1build1","1.3.0-1ubuntu0.18.04.0"],"ecosystem_specific":{"binaries":[{"binary_name":"isync","binary_version":"1.3.0-1ubuntu0.18.04.0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.0-2"],"ecosystem_specific":{"binaries":[{"binary_name":"isync","binary_version":"1.3.0-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.0-2.2","1.4.3-1","1.4.4-1","1.4.4-3","1.4.4-3ubuntu0.22.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"isync","binary_version":"1.4.4-3ubuntu0.22.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.4-5","1.4.4-5build2","1.4.4-5build3"],"ecosystem_specific":{"binaries":[{"binary_name":"isync","binary_version":"1.4.4-5build3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/isync?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.4-5build3","1.5.1-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"isync","binary_version":"1.5.1-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}},{"package":{"name":"isync","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/isync?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1-1ubuntu1","1.5.1-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.5.1-1ubuntu2","binary_name":"isync"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20247.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"Ubuntu","score":"low"}]}