ALINUX2-SA-2021%3A0033

Package updates are available for Alibaba Cloud Linux 2.1903 that fix the following vulnerabilities: 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.