Description
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.
References (7)
Core 7
Core References
Issue Tracking, Third Party Advisory x_refsource_misc
https://bugzilla.redhat.com/show_bug.cgi?id=1949442
Vendor Advisory x_refsource_misc
https://www.samba.org/samba/security/CVE-2021-20254.html
Third Party Advisory x_refsource_misc
https://security.netapp.com/advisory/ntap-20210430-0001/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202105-22
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2021/05/msg00023.html
Scores
CVSS v3
6.8
EPSS
0.0176
EPSS Percentile
82.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Details
CWE
CWE-125
Status
published
Products (6)
debian/debian_linux
9.0
fedoraproject/fedora
32
fedoraproject/fedora
33
redhat/enterprise_linux
7.0
redhat/enterprise_linux
8.0
samba/samba
3.6.0 - 4.12.15
Published
May 05, 2021
Tracked Since
Feb 18, 2026