Out-of-bounds read in Samba - CVE-2021-20254
Published: April 29, 2021 / Updated: July 27, 2022
Vulnerability identifier: #VU52748
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-20254
CWE-ID: CWE-125
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Samba
Affected software:
Samba
Samba
Detailed vulnerability description
The vulnerability allows a remote user to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when mapping Windows group identities (SIDs) into unix group identities (gids), which resulted into negative idmap cache entries created in the Samba server process token. An attacker who can manage to trigger the vulnerability can crash the Samba server or potentially perform unauthorized actions on the system.
How to mitigate CVE-2021-20254
Install updates from vendor's website.