Samba 4.16 Features added/changed: Difference between revisions

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Samba 4.16 is [[Samba_Release_Planning#Maintenance_Mode|'''Maintenance Mode''']].
Samba 4.16 is [[Samba_Release_Planning#Security_Fixes_Only_Mode|''''Security Fixes_Only Mode'']].

==Samba 4.16.8==
==Samba 4.16.8==
:Release Notes for Samba 4.16.8
:Release Notes for Samba 4.16.8

Revision as of 16:59, 9 March 2023

Samba 4.16 is ''Security Fixes_Only Mode.

Samba 4.16.8

Release Notes for Samba 4.16.8
December 15, 2022

This is the latest stable release of the Samba 4.16 release series.

It also contains security changes in order to address the following defects:

This is the Samba CVE for the Windows Kerberos RC4-HMAC Elevation of Privilege Vulnerability disclosed by Microsoft on Nov 8 2022.
A Samba Active Directory DC will issue weak rc4-hmac session keys for use between modern clients and servers despite all modern Kerberos implementations supporting the aes256-cts-hmac-sha1-96 cipher.
On Samba Active Directory DCs and members 'kerberos encryption types = legacy' would force rc4-hmac as a client even if the server supports aes128-cts-hmac-sha1-96 and/or aes256-cts-hmac-sha1-96.
This is the Samba CVE for the Windows Kerberos Elevation of Privilege Vulnerability disclosed by Microsoft on Nov 8 2022.
A service account with the special constrained delegation permission could forge a more powerful ticket than the one it was presented with.
The "RC4" protection of the NetLogon Secure channel uses the same algorithms as rc4-hmac cryptography in Kerberos, and so must also be assumed to be weak.

Note that there are several important behavior changes included in this release, which may cause compatibility problems interacting with system still expecting the former behavior. Please read the advisories of CVE-2022-37966, CVE-2022-38023, CVE-2022-37967 and CVE-2022-38023 carefully!

samba-tool got a new 'domain trust modify' subcommand

This allows "msDS-SupportedEncryptionTypes" to be changed on trustedDomain objects. Even against remote DCs (including Windows) using the --local-dc-ipaddress= (and other --local-dc-* options).

See 'samba-tool domain trust modify --help' for further details.

smb.conf changes

 Parameter Name                               Description             Default
 --------------                               -----------             -------
 allow nt4 crypto                             Deprecated              no
 allow nt4 crypto:COMPUTERACCOUNT             New
 kdc default domain supported enctypes        New (see manpage)
 kdc supported enctypes                       New (see manpage)
 kdc force enable rc4 weak session keys       New                     No
 reject md5 clients                           New Default, Deprecated Yes
 reject md5 servers                           New Default, Deprecated Yes
 server schannel                              Deprecated              Yes
 server schannel require seal                 New, Deprecated         Yes
 server schannel require seal:COMPUTERACCOUNT New
 winbind sealed pipes                         Deprecated              Yes

Changes since 4.16.7

  • Jeremy Allison <>
  • BUG 15224: pam_winbind uses time_t and pointers assuming they are of the same size.
  • Andrew Bartlett <>
  • Ralph Boehme <>
  • Stefan Metzmacher <>
  • Noel Power <>
  • BUG 15224: pam_winbind uses time_t and pointers assuming they are of the same size.
  • Anoop C S <>
  • BUG 15198: Prevent EBADF errors with vfs_glusterfs.
  • Andreas Schneider <>
  • Joseph Sutton <>
  • Nicolas Williams <>

Release Notes Samba 4.16.8

Samba 4.16.7

Release Notes for Samba 4.16.7
November 15, 2022

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

Samba's Kerberos libraries and AD DC failed to guard against integer overflows when parsing a PAC on a 32-bit system, which allowed an attacker with a forged PAC to corrupt the heap.

Changes since 4.16.6

  • Joseph Sutton <>
  • Nicolas Williams <>
Release Notes Samba 4.16.7

Samba 4.16.6

Release Notes for Samba 4.16.6
October 25, 2022

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

  • CVE-2022-3437: There is a limited write heap buffer overflow in the GSSAPI unwrap_des() and unwrap_des3() routines of Heimdal (included in Samba).

Changes since 4.16.5

  • Joseph Sutton <>
 Release Notes Samba 4.16.6

Samba 4.16.5

Release Notes for Samba 4.16.5

September 07, 2022

This is the latest stable release of the Samba 4.16 release series.

Changes since 4.16.4

  • Jeremy Allison <>
  • BUG 15128: Possible use after free of connection_struct when iterating smbd_server_connection->connections.
  • Ralph Boehme <>
  • BUG 15086: Spotlight RPC service returns wrong response when Spotlight is disabled on a share.
  • BUG 15126: acl_xattr VFS module may unintentionally use filesystem permissions instead of ACL from xattr.
  • BUG 15153: Missing SMB2-GETINFO access checks from MS-SMB2
  • BUG 15161: assert failed: !is_named_stream(smb_fname)") at ../../lib/util/fault.c:197.
  • Stefan Metzmacher <>
  • BUG 15148: Missing READ_LEASE break could cause data corruption.
  • Andreas Schneider <>
  • BUG 15124: rpcclient can crash using setuserinfo(2).
  • BUG 15132: Samba fails to build with glibc 2.36 caused by including <sys/mount.h> in libreplace.
  • Joseph Sutton <>
  • BUG 15152: SMB1 negotiation can fail to handle connection errors.
  • Michael Tokarev <>
  • BUG 15078: samba-tool domain join segfault when joining a samba ad domain.
 Release Notes Samba 4.16.5

Samba 4.16.4

Release Notes for Samba 4.16.4
July 27, 2022

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

Samba AD users can bypass certain restrictions associated with changing passwords.
Samba AD users can forge password change requests for any user.
Samba AD users can crash the server process with an LDAP add or modify request.
Samba AD users can induce a use-after-free in the server process with an LDAP add or modify request.
Server memory information leak via SMB1.

Changes since 4.16.3

  • Jeremy Allison <>
  • Andrew Bartlett <>
  • Andreas Schneider <>
  • Joseph Sutton <>
 Release Notes Samba 4.16.4

Samba 4.16.3

Release Notes for Samba 4.16.3
July 18, 2022

This is the latest stable release of the Samba 4.16 release series.

Changes since 4.16.2

  • Jeremy Allison <>
  • BUG 15099: Using vfs_streams_xattr and deleting a file causes a panic.
  • Douglas Bagnall <>
  • BUG 14986: Add support for bind 9.18.
  • BUG 15076: logging dsdb audit to specific files does not work.
  • Samuel Cabrero <>
  • BUG 14979: Problem when winbind renews Kerberos.
  • BUG 15095: Samba with new lorikeet-heimdal fails to build on gcc 12.1 in developer mode.
  • Volker Lendecke <>
  • BUG 15105: Crash in streams_xattr because fsp->base_fsp->fsp_name is NULL.
  • BUG 15118: Crash in rpcd_classic - NULL pointer deference in mangle_is_mangled().
  • Noel Power <>
  • BUG 15100: smbclient commands del & deltree fail with NT_STATUS_OBJECT_PATH_NOT_FOUND with DFS.
  • Christof Schmitt <>
  • BUG 15120: Fix check for chown when processing NFSv4 ACL.
  • Andreas Schneider <>
  • BUG 15082: The pcap background queue process should not be stopped.
  • BUG 15097: testparm: Fix typo in idmap rangesize check.
  • BUG 15106: net ads info returns LDAP server and LDAP server name as null.
  • BUG 15108: ldconfig: /lib64/ is not a symbolic link.
  • Martin Schwenke <>
  • BUG 15090: CTDB child process logging does not work as expected.
 Release Notes Samba 4.16.3

Samba 4.16.2

Release Notes for Samba 4.16.2
June 13, 2022

This is the latest stable release of the Samba 4.16 release series.

Changes since 4.16.1

  • Jeremy Allison <>
  • BUG 15042: Use pathref fd instead of io fd in vfs_default_durable_cookie.
  • Ralph Boehme <>
  • BUG 15069: vfs_gpfs with vfs_shadowcopy2 fail to restore file if original file had been deleted.
  • Samuel Cabrero <>
  • Samuel Cabrero <>
  • BUG 14674: net ads info shows LDAP Server: depending on contacted server.
  • Volker Lendecke <>
  • BUG 15062: Update from 4.15 to 4.16 breaks discovery of [homes] on standalone server from Win and IOS.
  • Stefan Metzmacher <>
  • BUG 15071: waf produces incorrect names for python extensions with Python 3.11.
  • Noel Power <>
  • BUG 15075: smbclient -E doesn't work as advertised.
  • Andreas Schneider <>
  • BUG 15071: waf produces incorrect names for python extensions with Python 3.11.
  • BUG 15081: The samba background daemon doesn't refresh the printcap cache on startup.

o Robert Sprowson <>

  • BUG 14443: Out-by-4 error in smbd read reply max_send clamp..
Release Notes Samba 4.16.2

Samba 4.16.1

Release Notes for Samba 4.16.1
May 02, 2022

This is the latest stable release of the Samba 4.16 release series.

Changes since 4.16.0

  • Jeremy Allison <>
  • BUG 14831: Share and server swapped in smbget password prompt.
  • BUG 15022: Durable handles won't reconnect if the leased file is written to.
  • BUG 15023: rmdir silently fails if directory contains unreadable files and hide unreadable is yes.
  • BUG 15038: SMB2_CLOSE_FLAGS_FULL_INFORMATION fails to return information on renamed file handle.
  • Andrew Bartlett <>
  • BUG 8731: Need to describe --builtin-libraries= better (compare with --bundled-libraries).
  • Ralph Boehme <>
  • BUG 14957: vfs_shadow_copy2 breaks "smbd async dosmode" sync fallback.
  • BUG 15035: shadow_copy2 fails listing snapshotted dirs with shadow:fixinodes.
  • Samuel Cabrero <>
  • BUG 15046: PAM Kerberos authentication incorrectly fails with a clock skew error.
  • Pavel Filipenský <>
  • 15041: Username map - samba erroneously applies unix group memberships to user account entries.
  • Stefan Metzmacher <>
  • Christof Schmitt <>
  • BUG 15027: Uninitialized litemask in variable in vfs_gpfs module.
  • BUG 15055: vfs_gpfs recalls=no option prevents listing files.
  • Andreas Schneider <>
  • BUG 15054: smbd doesn't handle UPNs for looking up names.
Release Notes Samba 4.16.1

Samba 4.16.0

Release Notes for Samba 4.16.0
March 21, 2022

Release Announcements

This is the first stable release of the Samba 4.16 release series. Please read the release notes carefully before upgrading.


New samba-dcerpcd binary to provide DCERPC in the member server setup

In order to make it much easier to break out the DCERPC services from smbd, a new samba-dcerpcd binary has been created.

samba-dcerpcd can be used in two ways. In the normal case without startup script modification it is invoked on demand from smbd or winbind --np-helper to serve DCERPC over named pipes. Note that in order to run in this mode the smb.conf [global] section has a new parameter "rpc start on demand helpers = [true|false]". This parameter is set to "true" by default, meaning no changes to smb.conf files are needed to run samba-dcerpcd on demand as a named pipe helper.

It can also be used in a standalone mode where it is started separately from smbd or winbind but this requires changes to system startup scripts, and in addition a change to smb.conf, setting the new [global] parameter "rpc start on demand helpers = false". If "rpc start on demand helpers" is not set to false, samba-dcerpcd will refuse to start in standalone mode.

Note that when Samba is run in the Active Directory Domain Controller mode the samba binary that provides the AD code will still provide its normal DCERPC services whilst allowing samba-dcerpcd to provide services like SRVSVC in the same way that smbd used to in this configuration.

The parameters that allowed some smbd-hosted services to be started externally are now gone (detailed below) as this is now the default setting.

samba-dcerpcd can also be useful for use outside of the Samba framework, for example, use with the Linux kernel SMB2 server ksmbd or possibly other SMB2 server implementations.

Heimdal-8.0pre used for Samba Internal Kerberos, adds FAST support

Samba has since Samba 4.0 included a snapshot of the Heimdal Kerberos implementation. This snapshot has now been updated and will closely match what will be released as Heimdal 8.0 shortly.

This is a major update, previously we used a snapshot of Heimdal from 2011, and brings important new Kerberos security features such as Kerberos request armoring, known as FAST. This tunnels ticket requests and replies that might be encrypted with a weak password inside a wrapper built with a stronger password, say from a machine account.

In Heimdal and MIT modes Samba's KDC now supports FAST, for the support of non-Windows clients.

Windows clients will not use this feature however, as they do not attempt to do so against a server not advertising domain Functional Level 2012. Samba users are of course free to modify how Samba advertises itself, but use with Windows clients is not supported "out of the box".

Finally, Samba also uses a per-KDC, not per-realm 'cookie' to secure part of the FAST protocol. A future version will align this more closely with Microsoft AD behaviour.

If FAST needs to be disabled on your Samba KDC, set

kdc enable fast = no

in the smb.conf.

The Samba project wishes to thank the numerous developers who have put in a massive effort to make this possible over many years. In particular we thank Stefan Metzmacher, Joseph Sutton, Gary Lockyer, Isaac Boukris and Andrew Bartlett. Samba's developers in turn thank their employers and in turn their customers who have supported this effort over many years.

Certificate Auto Enrollment

Certificate Auto Enrollment allows devices to enroll for certificates from Active Directory Certificate Services. It is enabled by Group Policy. To enable Certificate Auto Enrollment, Samba's group policy will need to be enabled by setting the smb.conf option `apply group policies` to Yes. Samba Certificate Auto Enrollment depends on certmonger, the cepces certmonger plugin, and sscep. Samba uses sscep to download the CA root chain, then uses certmonger paired with cepces to monitor the host certificate templates. Certificates are installed in /var/lib/samba/certs and private keys are installed in /var/lib/samba/private/certs.

Ability to add ports to dns forwarder addresses in internal DNS backend

The internal DNS server of Samba forwards queries non-AD zones to one or more configured forwarders. Up until now it has been assumed that these forwarders listen on port 53. Starting with this version it is possible to configure the port using host:port notation. See smb.conf for more details. Existing setups are not affected, as the default port is 53.

CTDB changes

  • The "recovery master" role has been renamed "leader"
Documentation and logs now refer to "leader".
The following ctdb tool command names have changed:
   recmaster -> leader
   setrecmasterrole -> setleaderrole
Command output has changed for the following commands:
The "[legacy] -> recmaster capability" configuration option has been renamed and moved to the cluster section, so this is now:
   [cluster] -> leader capability
  • The "recovery lock" has been renamed "cluster lock"
Documentation and logs now refer to "cluster lock".
The "[cluster] -> recovery lock" configuration option has been deprecated and will be removed in a future version. Please use "[cluster] -> cluster lock" instead.
If the cluster lock is enabled then traditional elections are not done and leader elections use a race for the cluster lock. This avoids various conditions where a node is elected leader but can not take the cluster lock. Such conditions included:
  • At startup, a node elects itself leader of its own cluster before connecting to other nodes
  • Cluster filesystem failover is slow
The abbreviation "reclock" is still used in many places, because a better abbreviation eludes us (i.e. "clock" is obvious bad) and changing all instances would require a lot of churn. If the abbreviation "reclock" for "cluster lock" is confusing, please consider mentally prefixing it with "really excellent".
  • CTDB now uses leader broadcasts and an associated timeout to determine if an election is required
The leader broadcast timeout can be configured via new configuration option
   [cluster] -> leader timeout
This specifies the number of seconds without leader broadcasts before a node calls an election. The default is 5.


Older SMB1 protocol SMBCopy command removed

SMB is a nearly 30-year old protocol, and some protocol commands that while supported in all versions, have not seen widespread use.

One of those is SMBCopy, a feature for a server-side copy of a file. This feature has been so unmaintained that Samba has no testsuite for it.

The SMB1 command SMB_COM_COPY (SMB1 command number 0x29) was introduced in the LAN Manager 1.0 dialect and it was rendered obsolete in the NT LAN Manager dialect.

Therefore it has been removed from the Samba smbd server.

We do note that a fully supported and tested server-side copy is present in SMB2, and can be accessed with "scopy" subcommand in smbclient)

SMB1 server-side wildcard expansion removed

Server-side wildcard expansion is another feature that sounds useful, but is also rarely used and has become problematic - imposing extra work on the server (both in terms of code and CPU time).

In actual OS design, wildcard expansion is handled in the local shell, not at the remote server using SMB wildcard syntax (which is not shell syntax).

In Samba 4.16 the ability to process file name wildcards in requests using the SMB1 commands SMB_COM_RENAME (SMB1 command number 0x7), SMB_COM_NT_RENAME (SMB1 command number 0xA5) and SMB_COM_DELETE (SMB1 command number 0x6) has been removed.

SMB1 protocol has been deprecated, particularly older dialects

We take this opportunity to remind that we have deprecated and disabled by default, but not removed, the whole SMB1 protocol since Samba 4.11. If needed for security purposes or code maintenance we will continue to remove older protocol commands and dialects that are unused or have been replaced in more modern SMB1 versions.

We specifically deprecate the older dialects older than "NT LM 0.12" (also known as "NT LANMAN 1.0" and "NT1").

Please note that "NT LM 0.12" is the dialect used by software as old as Windows 95, Windows NT and Samba 2.0, so this deprecation applies to DOS and similar era clients.

We do reassure that that 'simple' operation of older clients than these (eg DOS) will, while untested, continue for the near future, our purpose is not to cripple use of Samba in unique situations, but to reduce the maintaince burden.

Eventually SMB1 as a whole will be removed, but no broader change is announced for 4.16.

In the rare case where the above changes cause incompatibilities, users requiring support for these features will need to use older versions of Samba.

No longer using Linux mandatory locks for sharemodes

smbd mapped sharemodes to Linux mandatory locks. This code in the Linux kernel was broken for a long time, and is planned to be removed with Linux 5.15. This Samba release removes the usage of mandatory locks for sharemodes and the "kernel share modes" config parameter is changed to default to "no". The Samba VFS interface is kept, so that file-system specific VFS modules can still use private calls for enforcing sharemodes.

smb.conf changes

 Parameter Name                          Description     Default
 --------------                          -----------     -------
 kernel share modes                      New default     No
 dns forwarder                           Changed
 rpc_daemon                              Removed
 rpc_server                              Removed
 rpc start on demand helpers             Added           true


  • Andrew Bartlett <>
  • BUG 15000: Memory leak in FAST cookie handling.
  • Elia Geretto <>
  • BUG 14983: NT_STATUS_ACCESS_DENIED translates into EPERM instead of EACCES in SMBC_server_internal.
  • Stefan Metzmacher <>
  • BUG 13879: Simple bind doesn't work against an RODC (with non-preloaded users).
  • BUG 14641: Crash of winbind on RODC.
  • BUG 15001: LDAP simple binds should honour "old password allowed period".
  • BUG 15002: S4U2Self requests don't work against servers without FAST support.
  • BUG 15003: wbinfo -a doesn't work reliable with upn names.
  • BUG 15005: A cross-realm kerberos client exchanges fail using KDCs with and without FAST.
  • BUG 15015: PKINIT: hdb_samba4_audit: Unhandled hdb_auth_status=9 => INTERNAL_ERROR.
  • Garming Sam <>
  • BUG 13879: Simple bind doesn't work against an RODC (with non-preloaded users).
  • Andreas Schneider <>
  • BUG 15016: Regression: create krb5 conf = yes doesn't work with a single KDC.
  • Joseph Sutton <>
  • BUG 15015: PKINIT: hdb_samba4_audit: Unhandled hdb_auth_status=9 => INTERNAL_ERROR.


  • Jeremy Allison <>
  • BUG 14737: Samba does not response STATUS_INVALID_PARAMETER when opening 2 objects with same lease key.
  • Jule Anger <>
  • BUG 14999: Listing shares with smbstatus no longer works.
  • Douglas Bagnall <>
  • BUG 14996: Fix ldap simple bind with TLS auditing.
  • Andrew Bartlett <>
  • BUG 14995: Use Heimdal 8.0 (pre) rather than an earlier snapshot.
  • Volker Lendecke <>
  • BUG 14989: Fix a use-after-free in SMB1 server.
  • Stefan Metzmacher <>
  • BUG 14865: Uncached logon on RODC always fails once.
  • BUG 14984: Changing the machine password against an RODC likely destroys the domain join.
  • BUG 14993: authsam_make_user_info_dc() steals memory from its struct ldb_message *msg argument.
  • BUG 14995: Use Heimdal 8.0 (pre) rather than an earlier snapshot.
  • Joseph Sutton <>
  • BUG 14995: Use Heimdal 8.0 (pre) rather than an earlier snapshot.


  • Samuel Cabrero <>
  • BUG 14979: Problem when winbind renews Kerberos.
  • Björn Jacke <>
  • BUG 13631: DFS fix for AIX broken.
  • BUG 14974 : Solaris and AIX acl modules: wrong function arguments.
  • BUG 7239: Function aixacl_sys_acl_get_file not declared / coredump.
  • Andreas Schneider <>
  • BUG 14967: Samba autorid fails to map AD users if id rangesize fits in the id range only once.
  • Martin Schwenke <>
  • BUG 14958: CTDB can get stuck in election and recovery.


  • Jeremy Allison <>
  • BUG 14169: Renaming file on DFS root fails with NT_STATUS_OBJECT_PATH_NOT_FOUND.
  • BUG 14938: NT error code is not set when overwriting a file during rename in libsmbclient.
  • Ralph Boehme <>
  • BUG 14674: net ads info shows LDAP Server: depending on contacted server.
  • Pavel Filipenský <>
  • BUG 14971: virusfilter_vfs_openat: Not scanned: Directory or special file.
  • Volker Lendecke <>
  • BUG 14900: Regression: Samba 4.15.2 on macOS segfaults intermittently during strcpy in tdbsam_getsampwnam.
  • BUG 14975: Fix a crash in vfs_full_audit - CREATE_FILE can free a used fsp.
  • Stefan Metzmacher <>
  • BUG 14968: smb2_signing_decrypt_pdu() may not decrypt with gnutls_aead_cipher_decrypt() from gnutls before 3.5.2.
  • Andreas Schneider <>
  • BUG 14960: SDB uses HDB flags directly which can lead to unwanted side effects.


  • Jeremy Allison <jra at>
  • Ralph Boehme <slow at>
  • FeRD (Frank Dana) <ferdnyc at>
  • BUG 14947: samba-bgqd still notifying systemd, triggering log warnings without NotifyAccess=all.
  • Stefan Metzmacher <metze at>
  • BUG 14867: Printing no longer works on Windows 7 with 2021-10 monthly rollup patch.
  • BUG 14956: ndr_push_string() adds implicit termination for STR_NOTERM|REMAINING empty strings.
  • Joseph Sutton <josephsutton at>