SB2020102968 - Fedora 33 update for samba

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Main Vulnerability Database SB2020102968

SB2020102968 - Fedora 33 update for samba

Published: October 29, 2020 Updated: April 25, 2025

Security Bulletin ID SB2020102968
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


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

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


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)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


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) Memory corruption (CVE-ID: CVE-2020-14383)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to a boundary error when processing DNS records. A remote user

 with ability to create MX or NS records with absent properties can trigger the RPC service to dereference uninitialized memory and will result in denial of service attack against the RPC service.

Remediation

Install update from vendor's website.

References