CVE-2021-20254

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.

Summary:

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.

Reference Links(if available):

  • 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://lists.fedoraproject.org/archives/list/[email protected]/message/3EP2VJ73OVBPVSOSTVOMGIEQA3MWF6F7/
  • https://lists.fedoraproject.org/archives/list/[email protected]/message/ZAF6L2M6CNAJ2YYYGXPWETTW5YLCWTVT/
  • CVSS Score (if available)

    v2: / MEDIUMAV:N/AC:L/Au:S/C:P/I:P/A:N

    v3: / HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

    Links to Exploits(if available)