Samba 4.3.11 Available for Download

Samba 4.3.11 (gzipped)

Patch (gzipped) against Samba 4.3.10

                   Release Notes for Samba 4.3.11
                            July 07, 2016

This is a security release in order to address the following defect:

o  CVE-2016-2119 (Client side SMB2/3 required signing can be downgraded)


o  CVE-2016-2119:
   It's possible for an attacker to downgrade the required signing for
   an SMB2/3 client connection, by injecting the SMB2_SESSION_FLAG_IS_GUEST

   This means that the attacker can impersonate a server being connected to by
   Samba, and return malicious results.

   The primary concern is with winbindd, as it uses DCERPC over SMB2 when talking
   to domain controllers as a member server, and trusted domains as a domain
   controller.  These DCE/RPC connections were intended to protected by the
   combination of "client ipc signing" and
   "client ipc max protocol" in their effective default settings
   ("mandatory" and "SMB3_11").

   Additionally, management tools like net, samba-tool and rpcclient use DCERPC
   over SMB2/3 connections.

   By default, other tools in Samba are unprotected, but rarely they are
   configured to use smb signing, via the "client signing" parameter (the default
   is "if_required").  Even more rarely the "client max protocol" is set to SMB2,
   rather than the NT1 default.

   If both these conditions are met, then this issue would also apply to these
   other tools, including command line tools like smbcacls, smbcquota, smbclient,
   smbget and applications using libsmbclient.

Changes since 4.3.10:

o  Stefan Metzmacher <>
   * BUG 11860: CVE-2016-2119: Fix client side SMB2 signing downgrade.
   * BUG 11948: Total dcerpc response payload more than 0x400000.