{"id":"DEBIAN-CVE-2023-4091","details":"A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS module \"acl_xattr\" is configured with \"acl_xattr:ignore system acls = yes\". The SMB protocol allows opening files when the client requests read-only access but then implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create disposition request. The issue arises in configurations that bypass kernel file system permissions checks, relying solely on Samba's permissions.","modified":"2026-09-15T09:02:37.986115368Z","published":"2023-11-03T08:15:08.197Z","upstream":["CVE-2023-4091"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2023-4091"}],"affected":[{"package":{"name":"samba","ecosystem":"Debian:12","purl":"pkg:deb/debian/samba?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:4.17.12+dfsg-0+deb12u1"}]}],"versions":["2:4.17.10+dfsg-0+deb12u1","2:4.17.10+dfsg-0+deb12u1~bpo11+1","2:4.17.11+dfsg-0+deb12u1","2:4.17.12+dfsg-0+deb12u1~bpo11+1","2:4.17.8+dfsg-2","2:4.17.8+dfsg-2.1","2:4.17.9+dfsg-0+deb12u1","2:4.17.9+dfsg-0+deb12u2","2:4.17.9+dfsg-0+deb12u3","2:4.17.9+dfsg-0+deb12u3~bpo11+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-4091.json"}},{"package":{"name":"samba","ecosystem":"Debian:13","purl":"pkg:deb/debian/samba?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:4.19.1+dfsg-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-4091.json"}},{"package":{"name":"samba","ecosystem":"Debian:14","purl":"pkg:deb/debian/samba?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:4.19.1+dfsg-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2023-4091.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}