Synopsis
Moderate: samba security 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):
- It was found that samba did not enforce "SMB signing" when certain configuration options were enabled. A remote attacker could launch a man-in-the-middle attack and retrieve information in plain-text. (CVE-2017-12150)
- A flaw was found in the way samba client used encryption with the max protocol set as SMB3. The connection could lose the requirement for signing and encrypting to any DFS redirects, allowing an attacker to read or alter the contents of the connection via a man-in-the-middle attack. (CVE-2017-12151)
- An information leak flaw was found in the way SMB1 protocol was implemented by Samba. A malicious client could use this flaw to dump server memory contents to a file on the samba share or to a shared printer, though the exact area of server memory cannot be controlled by the attacker. (CVE-2017-12163)
Red Hat would like to thank the Samba project for reporting CVE-2017-12150 and CVE-2017-12151 and Yihan Lian and Zhibin Hu (Qihoo 360 GearTeam), Stefan Metzmacher (SerNet), and Jeremy Allison (Google) for reporting CVE-2017-12163. Upstream acknowledges Stefan Metzmacher (SerNet) as the original reporter of CVE-2017-12150 and CVE-2017-12151.
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
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Red Hat Enterprise Linux Server 7 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.6 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.5 x86_64
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Red Hat Enterprise Linux Server - Extended Update Support 7.4 x86_64
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Red Hat Enterprise Linux Workstation 7 x86_64
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Red Hat Enterprise Linux for IBM z Systems 7 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
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Red Hat Enterprise Linux for Power, big endian 7 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
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Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
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Red Hat Enterprise Linux for Scientific Computing 7 x86_64
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Red Hat Enterprise Linux Resilient Storage (for RHEL Server) 7 x86_64
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Red Hat Enterprise Linux Resilient Storage (for RHEL Server) - Extended Update Support 7.6 x86_64
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Red Hat Enterprise Linux Resilient Storage (for RHEL Server) - Extended Update Support 7.5 x86_64
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Red Hat Enterprise Linux Resilient Storage (for RHEL Server) - Extended Update Support 7.4 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
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Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
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Red Hat Enterprise Linux Server - AUS 7.6 x86_64
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Red Hat Enterprise Linux Server - AUS 7.4 x86_64
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Red Hat Enterprise Linux Desktop 7 x86_64
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Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
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Red Hat Enterprise Linux for Power, little endian 7 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
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Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
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Red Hat Enterprise Linux Resilient Storage (for IBM z Systems) 7 s390x
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Red Hat Enterprise Linux Server - TUS 7.6 x86_64
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Red Hat Enterprise Linux Server - TUS 7.4 x86_64
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
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Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
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Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
Fixes
- BZ - 1488197 - CVE-2017-12151 samba: SMB2 connections don't keep encryption across DFS redirects
- BZ - 1488400 - CVE-2017-12150 samba: Some code path don't enforce smb signing, when they should
- BZ - 1491206 - CVE-2017-12163 Samba: Server memory information leak over SMB1
CVEs
References
Vulmon