====================================================================
== Subject:     Server memory information leak via SMB1 only.
==
== CVE ID#:     CVE-2022-TBD
==
== Versions:    All versions of Samba.
==
== Summary:     SMB1 Client with write access to a share can cause
==              server memory contents to be written into a file
==              or printer.
==
====================================================================

===========
Description
===========

Please note that SMB1 is *NOT* enabled by default, only sites where
SMB1 has been enabled by the administrator are vulnerable to this bug.

All versions of Samba are vulnerable to a server memory information
leak bug over SMB1 if a client can write data to a share. Some SMB1
write requests were not correctly range checked to ensure the client
had sent enough data to fulfill the write, allowing server memory
contents to be written into the file (or printer) instead of client
supplied data. The client cannot control the area of the server memory
that is written to the file (or printer).

==================
Patch Availability
==================

A patch addressing this defect has been posted to

  http://www.samba.org/samba/security/

Additionally, Samba 4.16.x, 4.15.x and 4.14.x have been issued as
security releases to correct the defect. Patches against older Samba
versions are available at http://samba.org/samba/patches/. Samba
vendors and administrators running affected versions are advised to
upgrade or apply the patch as soon as possible.

==================
CVSSv3.1 calculation
==================

CVSS:AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C/CR:M/IR:L/AR:L/MAV:N/MAC:H/MPR:L/MUI:N/MS:U/MC:X/MI:N/MA:N

base score of 2.9

==========
Workaround
==========

This is an SMB1-only vulnerability. Since Samba release 4.11.0 SMB1
has been disabled by default. Do not turn on SMB1 serving unless
required for your specific clients.

=======
Credits
=======

This problem was reported by Luca Moro working with Trend Micro Zero
Day Initiative. Jeremy Allison of Google and the Samba Team provided
the fix.