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RE: Possible security problem with svnsync?

From: Jon Foster <Jon.Foster_at_cabot.co.uk>
Date: Wed, 12 May 2010 15:49:20 +0100

Hi,
 
Bob Archer wrote:
> Jon Foster wrote:
> > I have a repository that is partially mirrored, using svnsync and
> > mod_authz_svn [1]. I just realised that the administrator of the
> > mirror server can bypass the authz rules I've set up on the master
> > server. All he has to do is change the svn:sync-from-url property
> > on the mirror repository to be a file:// URL to the source
> > repository, rather than a http:// one. The correct file:// URL is
> > probably guessable.
>
> Well, this has nothing to do with svnsync then does it? If you
> expose the repository file system then yes anyone can access it
> bypassing the server. Even with svn.exe it can be done. you should
> use FS/Network permission so that your repositories are only
> available via your server (http or svn protocols).

I'm not exposing the repository file system to users, and I'm not
giving shell access to users. The only way a user can access this
server is via Apache. However, svnsync is started by the post-commit
hook. (This is the recommended svnsync setup, as far as I can tell).
This means that svnsync is running on the server, as the "apache"
user, which gives it a lot of permissions - including the ability
to directly access the repository files.

The problem is that svnsync trusts the mirror server to give it the
correct source URL.

Kind regards,

Jon Foster

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Received on 2010-05-12 16:50:06 CEST

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