[cifs-protocol] [REG:111052652308584] [ttalpey at microsoft.com: Reminder -- share secdesc and smb2 echo?]

Volker Lendecke Volker.Lendecke at SerNet.DE
Sun Jun 12 03:16:50 MDT 2011

On Fri, Jun 10, 2011 at 03:57:19PM +0000, Obaid Farooqi wrote:
> Your observation is correct, and it is the case that the
> CIFS, SMB or SMB2 server MUST first verify that the
> Share.FileSecurity allows the client-supplied
> DesiredAccess. If any of the nonzero bits of DesiredAccess
> are not permitted for the user by the Share.FileSecurity,
> the server MUST fail the request with

Thanks. This is for the ntcreate call, right?

> Please let me know if it answers your question. If it
> does, I'll consider this issue resolved.

It does not fully answer it, sorry. Attached find a network
trace against the server where user "vlendec" (the one I'm
connecting as) does not have the "full access" right as in
the last traces. However, in frames 38/39 it seems that I
was able to create a new file, giving it a custom security
descriptor. I would have thought that when setting secdescs
is forbidden then creating a new file would not allow me to
set custom file descriptors using the nttrans create call.
This way it is possible for a user to circumvent the
non-ability to set secdescs by just making a copy into a new

BTW, the trace is from re-syncing an offline folder after
the server came back.

Can you explain that or show where this exception is
documented? And, will this end up in the documentation



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