SB2021100615 - Red Hat Gluster Storage Server for On-premise update for samba 

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Main Vulnerability Database SB2021100615

SB2021100615 - Red Hat Gluster Storage Server for On-premise update for samba

Published: October 6, 2021 Updated: January 7, 2024

Security Bulletin ID SB2021100615
Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 25% Medium 50% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-14318)

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to the way "ChangeNotify" concept for SMB1/2/3 protocols was implemented in Samba. A missing permissions check on a directory handle requesting ChangeNotify means that a client with a directory handle open only for FILE_READ_ATTRIBUTES (minimal access rights) could be used to obtain change notify replies from the server. These replies contain information that should not be available to directory handles open for FILE_READ_ATTRIBUTE only. A local unprivileged user can abuse this lack of permissions check to obtain information about file changes.


2) NULL pointer dereference (CVE-ID: CVE-2020-14323)

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error when processing requests in winbind in Samba. A remote user can send specially crafted request to winbind daemon, trigger a NULL pointer dereference error and crash it.


3) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2020-1472)

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions in Netlogon. A remote non-authenticated attacker can use MS-NRPC to connect to a domain controller to obtain domain administrator access. This vulnerability was dubbed ZeroLogon.


4) Out-of-bounds read (CVE-ID: CVE-2021-20254)

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.


Remediation

Install update from vendor's website.

References