Vulnerabilities > CVE-2021-20254 - Out-of-bounds Read vulnerability in multiple products
Attack vector
NETWORK Attack complexity
HIGH Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
NONE 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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Overread Buffers An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.
References
- 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/