Attachment 15010 Details for Bug 13851 – v3 of the advisory.

v3 of the advisory.

CVE-2019-3880-advisory-03.txt (text/plain), 1.95 KB, created by Jeremy Allison on 2019-03-27 17:56:37 UTC

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Creator: Jeremy Allison

Created: 2019-03-27 17:56:37 UTC

Size: 1.95 KB

patch

obsolete

>===========================================================
>== Subject:     Save registry file outside share as unprivileged user
>==
>== CVE ID#:     CVE-2019-3880
>==
>== Versions:    All versions of Samba since Samba 3.2.0
>==
>== Summary:     Authenticated users with write permission
>                can trigger a symlink traversal to write
>		files outside the Samba share.
>===========================================================
>
>===========
>Description
>===========
>
>Samba contains an RPC endpoint emulating the Windows registry service
>API. One of the requests, "winreg_SaveKey", is susceptible to a
>path/symlink traversal vulnerability. Unprivileged users can use it to
>save a registry hive file anywhere they have write access, even
>outside a Samba share.
>
>Samba writes the file as the authenticated user, not as root.
>
>==================
>Patch Availability
>==================
>
>Patches addressing both these issues have been posted to:
>
>    http://www.samba.org/samba/security/
>
>Additionally, Samba 4.8.11, 4.9.6 and 4.10.2 have been issued as
>security releases to correct the defect.  Samba administrators are
>advised to upgrade to these releases or apply the patch as soon as
>possible.
>
>==================
>CVSSv3 calculation
>==================
>
>CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N (5.4)
>
>==========
>Workaround
>==========
>
>A read only share (via filesystem permissions) containing no symbolic
>links will mitigate the attack.  For a write-enabled share containing
>no symbolic links, setting the global parameter 'unix extensions = no'
>or 'min protocol = SMB2' in the smb.conf will mitigate the attack.
>
>=======
>Credits
>=======
>
>Originally reported by Michael Hanselmann.
>
>Patches provided by Jeremy Allison of the Samba Team and Google.
>Advisory written by Andrew Bartlett of the Samba Team and Catalyst.
>
>==========================================================
>== Our Code, Our Bugs, Our Responsibility.
>== The Samba Team
>==========================================================

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