[Samba] Wide links and insecure wide links

Stilez stilezy at gmail.com
Wed Feb 28 19:30:45 UTC 2018


Thanks - that much I (pretty much) got.

Its really the "wide links" option that isn't well distinguished/clarified.

 *insecure* wide links is much more clear, although the detail you've given 
helps a lot.

What exactly is the "ordinary" "wide links = yes" option going to do (with 
or without Unix extensions), and how does it compare/how much exposure to 
mischief does it expose?


On 28 February 2018 18:20:02 Jeremy Allison <jra at samba.org> wrote:

> On Wed, Feb 28, 2018 at 01:39:09PM +0000, Stilez via samba wrote:
>> I'd like to understand reasonably fully,, the difference between the two
>> options "wide links" and "allow insecure wide links" in smb.conf. The docs
>> make them sound very similar but as there are obvious security implications
>> for anything to do with symlink scope, it's important to know what each of
>> them allows/blocks and where they differ.
>
> Setting "allow insecure wide links" to true allows
> clients to create SMB1 UNIX extension symlinks on
> the server filesystem that *THE SERVER WILL FOLLOW*.
>
> You can see why this is a problem. The SMB2 UNIX
> extensions will eliminate this possibility by
> changing client-stored symlinks into a datastore
> that the server will never follow. SMB2 UNIX extensions
> are currently being coded up as a test branch (not
> even experimental yet).





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