{"id":"CVE-2021-20254","details":"A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity.","modified":"2026-03-20T11:38:30.333636Z","published":"2021-05-05T14:15:07.883Z","related":["ALSA-2021:4058","MGASA-2021-0287","SUSE-SU-2021:1438-1","SUSE-SU-2021:1439-1","SUSE-SU-2021:1440-1","SUSE-SU-2021:1442-1","SUSE-SU-2021:1444-1","SUSE-SU-2021:1445-1","SUSE-SU-2021:14709-1","SUSE-SU-2021:1492-1","SUSE-SU-2021:1498-1","SUSE-SU-2021:3187-1","SUSE-SU-2022:0361-1","openSUSE-SU-2021:0636-1","openSUSE-SU-2021:3187-1","openSUSE-SU-2024:11365-1"],"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202105-22"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20210430-0001/"},{"type":"ADVISORY","url":"https://www.samba.org/samba/security/CVE-2021-20254.html"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1949442"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/samba-team/samba","events":[{"introduced":"b1d9ddf738c6e59e489bc9c339ce6de5988b689e"},{"fixed":"703c6301013f78e80882abfe8375d6a45a176b7f"},{"introduced":"3fe82c204f0d88cb6db50b7bd1f798b591a918f8"},{"fixed":"058aaad5f4a2399dc0c11b42a6650c251957f24d"},{"introduced":"9b49519cae3e967af9ea48dc5fcfb6c145e31db4"},{"fixed":"e29fc62e1d60a1add177fca059d0d67dcf6a1866"}],"database_specific":{"versions":[{"introduced":"3.6.0"},{"fixed":"4.12.15"},{"introduced":"4.13.0"},{"fixed":"4.13.8"},{"introduced":"4.14.0"},{"fixed":"4.14.4"}]}}],"versions":["ldb-2.2.1","ldb-2.3.0","samba-4.13.0","samba-4.13.1","samba-4.13.2","samba-4.13.3","samba-4.13.4","samba-4.13.5","samba-4.13.6","samba-4.13.7","samba-4.14.0","samba-4.14.1","samba-4.14.2","samba-4.14.3"],"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"32"}]},{"events":[{"introduced":"0"},{"last_affected":"33"}]},{"events":[{"introduced":"0"},{"last_affected":"7.0"}]},{"events":[{"introduced":"0"},{"last_affected":"8.0"}]},{"events":[{"introduced":"0"},{"last_affected":"9.0"}]}],"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-20254.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}