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Samba.org: Samba Team Releases Samba 2.2.7

Nov 20, 2002, 16:00 (4 Talkback[s])

The Samba Team is proud to announce the release of Samba 2.2.7.

A security hole has been discovered in versions 2.2.2 through 2.2.6
of Samba that could potentially allow an attacker to gain root access
on the target machine.  The word "potentially" is used because there
is no known exploit of this bug, and the Samba Team has not been able to
craft one ourselves. However, the seriousness of the problem warrants
this immediate 2.2.7 release.

In addition to addressing this security issue, Samba 2.2.7 also includes
thirteen unrelated improvements. These improvements result from our
process of continuous quality assurance and code review, and are part of
the Samba team's commitment to excellence.

The source code can be downloaded from :

    http://download.samba.org/samba/ftp/

All current source releases have been signed as well using the 
Samba Distribution Key (http://web/samba/ftp/samba-pubkey.asc)

Binary packages for major platforms can be found at

    http://download.samba.org/samba/ftp/Binary_Packages/

The release notes follow.

As always, all bugs are our responsibility.

                                  --Enjoy
                                  The Samba Team



            WHAT'S NEW IN Samba 2.2.7 - 20th November 2002
            ==============================================

This is the latest stable release of Samba. This is the version
that all production Samba servers should be running for all current
bug-fixes.

IMPORTANT: Security bugfix for Samba
- ------------------------------------

Summary
- -------

A security hole has been discovered in versions 2.2.2 through 2.2.6
of Samba that could potentially allow an attacker to gain root access
on the target machine.  The word "potentially" is used because there
is no known exploit of this bug, and the Samba Team has not been able to
craft one ourselves. However, the seriousness of the problem warrants
this immediate 2.2.7 release.

In addition to addressing this security issue, Samba 2.2.7 also includes
thirteen unrelated improvements. These improvements result from our
process of continuous quality assurance and code review, and are part of
the Samba team's commitment to excellence.

Details
- -------

There was a bug in the length checking for encrypted password change
requests from clients. A client could potentially send an encrypted
password, which, when decrypted with the old hashed password could be
used as a buffer overrun attack on the stack of smbd. The attach would
have to be crafted such that converting a DOS codepage string to little
endian UCS2 unicode would translate into an executable block of code.

All versions of Samba between 2.2.2 to 2.2.6 inclusive are vulnerable
to this problem. This version of Samba 2.2.7 contains a fix for this
problem.

Earlier versions of Samba are not vulnerable.

There is no known exploit or exploit code for this vulnerability,
it was discovered by a code audit by Debian Samba maintainers.

Credit
- ------

Thanks to Steve Langasek  and Eloy Paris
 for bringing this vulnerability to our notice.

Patch for Samba versions 2.2.2 to 2.2.6
- ---------------------------------------

The following patch applies cleanly to the above Samba versions
and will fix the vulnerability for sites that do not wish to upgrade
to 2.2.7 at this time.

- -------------------------------cut here---------------------------------
- --- libsmb/smbencrypt.c.orig    Tue Nov 19 17:21:57 2002
+++ libsmb/smbencrypt.c Tue Nov 19 17:22:12 2002
@@ -63,7 +63,7 @@
        if(len > 128)
                len = 128;
        /* Password must be converted to NT unicode - null terminated. */
- -       dos_struni2((char *)wpwd, (const char *)passwd, 256);
+       dos_struni2((char *)wpwd, (const char *)passwd, len);
        /* Calculate length in bytes */
        len = strlen_w((const smb_ucs2_t *)wpwd) * sizeof(int16);
- -------------------------------cut here---------------------------------


Changes since 2.2.6
- --------------------

See the cvs log for SAMBA_2_2 for more details

1)  ensure we send the notify message in the same way it is expected
    to be received by srv_spoolss_receive_message().
2)  attribute matching on truncate only matters when opening truncate
    with current SYSTEM|HIDDEN -> NONE. It's fine to truncate on open
    with current NONE -> SYSTEM | HIDDEN.
3)  Fix bug in rpcclient's deldriver command
4)  Don't set global_machinepasswordneeds_changing if
    lp_machine_password_timeout() is set to zero
5)  don't parse the BUFFER5 if the buffer length is zero
6)  fix core dump if pdbedit is run as non-root or smbpasswd file does
    not exist
7)  Ensure can_delete() returns correct error code
8)  correctly return NT_STATUS_DELETE_PENDING from open code
9)  fix bug that assumed dos_unistr2 length was in ucs2 units, not bytes
10) check the long_archi name is not null when deleting a printer driver.
    fixes core dump in smbd when using rpcclient's deldriver
11) fix fd leak with kernel change notify on Linux 2.4 kernels
12) must add one to the extra_data size to transfer the 0 string
    terminator.  This was causing "wbinfo --sequence" to access past the
    end of malloced memory
13) fix for large systems allowing more than 65536 files open in
    NTcreate&X
14) Fix bug in %U expansion

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