Published: 05/05/2021 Updated: 07/11/2023

CVSS v2 Base Score: 4.9 | Impact Score: 4.9 | Exploitability Score: 6.8

CVSS v3 Base Score: 6.8 | Impact Score: 5.2 | Exploitability Score: 1.6

VMScore: 436

Vector: AV:N/AC:M/Au:S/C:P/I:P/A:N

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.

Vulnerable Product	Search on Vulmon	Subscribe to Product
samba samba
fedoraproject fedora 32
fedoraproject fedora 33
redhat enterprise linux 7.0
redhat enterprise linux 8.0
debian debian linux 9.0

Debian Bug report logs - #987811 samba: CVE-2021-20254 Package: src:samba; Maintainer for src:samba is Debian Samba Maintainers <pkg-samba-maint@listsaliothdebianorg>; Reported by: Salvatore Bonaccorso <carnil@debianorg> Date: Fri, 30 Apr 2021 04:45:01 UTC Severity: grave Tags: security, upstream Found in versio ...

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 ...

A flaw was found in the way samba implemented SMB1 authentication An attacker could use this flaw to retrieve the plaintext password sent over the wire even if Kerberos authentication was required (CVE-2016-2124) A flaw was found in the way Samba maps domain users to local users An authenticated attacker could use this flaw to cause possible pri ...

A security issue has been found in all versions of the Samba file server since Samba 360 A coding error converting SIDs to gids could allow unexpected group entries in a process token This could allow unauthorized access to files The issue is fixed in Samba 4144, 4138 and 41215 ...

CWE-125 https://security.netapp.com/advisory/ntap-20210430-0001/https://www.samba.org/samba/security/CVE-2021-20254.html https://bugzilla.redhat.com/show_bug.cgi?id=1949442 https://security.gentoo.org/glsa/202105-22 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://bugs.debian.org/cgi-bin/bugreport.cgi?bug=987811 https://nvd.nist.gov https://alas.aws.amazon.com/AL2/ALAS-2021-1680.html

CVE-2021-20254

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