CVSS 3.1
6.8 mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NCVE-2021-20254
Medium (6.8). EPSS 1.6% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 1.6% chance of exploitation in the next 30 days; higher than 76% of CVEs (scores of 2026-10-31)
- CWE
- CWE-125
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- fedoraproject:fedora
- redhat:enterprise_linux
- samba:samba
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1949442
- https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/
- https://security.gentoo.org/glsa/202105-22