Samba 4.10.18 Available for Download
=============================== Release Notes for Samba 4.10.18 September 18, 2020 =============================== This is a security release in order to address the following defect: o CVE-2020-1472: Unauthenticated domain takeover via netlogon ("ZeroLogon"). The following applies to Samba used as domain controller only (most seriously the Active Directory DC, but also the classic/NT4-style DC). Installations running Samba as a file server only are not directly affected by this flaw, though they may need configuration changes to continue to talk to domain controllers (see "file servers and domain members" below). The netlogon protocol contains a flaw that allows an authentication bypass. This was reported and patched by Microsoft as CVE-2020-1472. Since the bug is a protocol level flaw, and Samba implements the protocol, Samba is also vulnerable. However, since version 4.8 (released in March 2018), the default behaviour of Samba has been to insist on a secure netlogon channel, which is a sufficient fix against the known exploits. This default is equivalent to having 'server schannel = yes' in the smb.conf. Therefore versions 4.8 and above are not vulnerable unless they have the smb.conf lines 'server schannel = no' or 'server schannel = auto'. Samba versions 4.7 and below are vulnerable unless they have 'server schannel = yes' in the smb.conf. Note each domain controller needs the correct settings in its smb.conf. Vendors supporting Samba 4.7 and below are advised to patch their installations and packages to add this line to the [global] section if their smb.conf file. The 'server schannel = yes' smb.conf line is equivalent to Microsoft's 'FullSecureChannelProtection=1' registry key, the introduction of which we understand forms the core of Microsoft's fix. Some domains employ third-party software that will not work with a 'server schannel = yes'. For these cases patches are available that allow specific machines to use insecure netlogon. For example, the following smb.conf: server schannel = yes server require schannel:triceratops$ = no server require schannel:greywacke$ = no will allow only "triceratops$" and "greywacke$" to avoid schannel. More details can be found here: https://www.samba.org/samba/security/CVE-2020-1472.html Changes since 4.10.17 --------------------- o Jeremy Allison <firstname.lastname@example.org> * BUG 14497: CVE-2020-1472(ZeroLogon): s3:rpc_server/netlogon: Protect netr_ServerPasswordSet2 against unencrypted passwords. o Günther Deschner <email@example.com> * BUG 14497: CVE-2020-1472(ZeroLogon): s3:rpc_server/netlogon: Support "server require schannel:WORKSTATION$ = no" about unsecure configurations. o Bjoern Jacke <firstname.lastname@example.org> * BUG 14422: util: Fix build on AIX by fixing the order of replace.h include. o Gary Lockyer <email@example.com> * BUG 14497: CVE-2020-1472(ZeroLogon): s4 torture rpc: repeated bytes in client challenge. o Stefan Metzmacher <firstname.lastname@example.org> * BUG 14497: CVE-2020-1472(ZeroLogon): libcli/auth: Reject weak client challenges in netlogon_creds_server_init() "server require schannel:WORKSTATION$ = no" o Martin Schwenke <email@example.com> * BUG 14415: Fix build on FreeBSD.
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