Moderate: samba security and bug fix update

Synopsis

Moderate: samba security and bug fix update

Type/Severity

Security Advisory: Moderate

Topic

An update for samba is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

Samba is an open-source implementation of the Server Message Block (SMB) protocol and the related Common Internet File System (CIFS) protocol, which allow PC-compatible machines to share files, printers, and various information.

Security Fix(es):

• samba: Netlogon elevation of privilege vulnerability (Zerologon) (CVE-2020-1472)
  
• samba: Missing handle permissions check in SMB1/2/3 ChangeNotify (CVE-2020-14318)
  
• samba: Unprivileged user can crash winbind (CVE-2020-14323)
  

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

• The 'require_membership_of' documentation in pam_winbind manpage is incorrect (BZ#1853272)
  
• Malfunctioning %U substitution in valid users option (BZ#1868917)
  
• Regression: smbd and nmbd are restarted when samba-winbind package is upgraded (BZ#1878205)
  
• winbindd memory leak on wbinfo -u with security=ADS (BZ#1892313)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing this update, the smb service will be restarted automatically.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Resilient Storage for x86_64 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux Resilient Storage for IBM z Systems 7 s390x
• Red Hat Enterprise Linux Resilient Storage for Power, little endian 7 ppc64le

Fixes

• BZ - 1853272 - The 'require_membership_of' documentation in pam_winbind manpage is incorrect [rhel-7.9.z]
• BZ - 1868917 - Malfunctioning %U substitution in valid users option [rhel-7.9.z]
• BZ - 1878205 - Regression: smbd and nmbd are restarted when samba-winbind package is upgraded [rhel-7.9.z]
• BZ - 1879822 - CVE-2020-1472 samba: Netlogon elevation of privilege vulnerability (Zerologon)
• BZ - 1891685 - CVE-2020-14323 samba: Unprivileged user can crash winbind
• BZ - 1892313 - winbindd memory leak on wbinfo -u with security=ADS [rhel-7.9.z]
• BZ - 1892631 - CVE-2020-14318 samba: Missing handle permissions check in SMB1/2/3 ChangeNotify

CVEs

• CVE-2020-1472
• CVE-2020-14318
• CVE-2020-14323

References

• https://access.redhat.com/security/updates/classification/#moderate