/usr/bin/dspamc file permissions incorrect

[Swâmi Petaramesh]

Binary package hint: dspam

/usr/bin/dspamc file permissions should be the same as for /usr/bin/dspam (owned by dspam:dspam, setgid bit set) otherwise calling it as non-root causes it to complain it cannot read /etc/dspam/dspam.conf, and abort.

[Daniel Hahler (blueyed)]

IMHO this should be decided in Debian (or by somebody really into this).

I'm not using dspam/dspamc myself, but setuid/setgid programs should be kept to a minimum.

While researching this, I've found a patch for this from dspam-users (http://mailing-list.nuclearelephant.com/0658.html) and another one for a --config option, which would allow to use another config file instead (http://osdir.com/ml/mail.spam.dspam.devel/2006-05/msg00026.html).

Is dspamc as shipped in Debian/Ubuntu not usable at all currently? Or only for user root?

[Swâmi Petaramesh (swami-petaramesh)]

Both the "dspam" and "dspamc" binaries perform the same function : Check a message for being spam or not, and either one or the other is used by MTA or MDA (or any user on the system).

"dspam" can be run either one-shot or as a daemon. "dspamc" is actually just a lighter, stripped-down version of dspam (which means logically, more secure), that can only act as a client to "dspam" running in daemon mode.

Which means that one processes a message either with one-shot dspam (slow startup and databases opening), or with a dspam running as a daemon, sending messages to the lighter "dspamc" which is the client to the daemon.

"dspam" comes sgid dspam, "dspamc" should as well. There's no reason why the first would be and not the 2nd. With the current package, calling "dspam" will work for any user, where calling "dspamc" won't, which is abnormal (for dspamc will be unable to read its config file). Here' calling dspamc will work only for the users dspam or root, or for a user which is part of the dspam group. This is unfortunate as several users need to be able to call it (MTA, MDA, Apache from the dspam web interface), plus any system user whot may need to retrain messages or learn spam/ham corpus manually.

I don't see no issue putting "dspamc" sgid dspam where "dspam" already is. We're not talking of "suid root" here, and the dspam user has no specific overall rights on the system, just the right to access its own files..

I've used dspam for years now, so I believe I know quite well how it works ;-)

[Swâmi Petaramesh (swami-petaramesh)]

Just adding : Calling "dspamc" is functionally equivalent to calling "dspam --client", but the dspamc binary is much lighter.

[Daniel Hahler (blueyed)]

Thanks for your explanation, I've created a patch to fix this.

[Daniel Hahler (blueyed)]

This patch fixes this bug.
It includes a changelog entry to close bug 158252 correctly in Hardy: it was referenced wrong in the previous upload.

[Emmet Hikory (persia)]

Uploaded. Thanks.

[Daniel Hahler (blueyed)]

dspam (3.6.8-5ubuntu3) hardy; urgency=low

  * Close the right bug (158269 is not dspam) (LP: #158252)
  * debian/dspam.post{inst,rm}: apply same setgid permissions to
    /usr/bin/dspamc as with /usr/bin/dspam (LP: #158136)
  * debian/rules: Fix debian-rules-ignores-make-clean-error

 -- dAniel hAhler <email address hidden> Tue, 06 Nov 2007 10:29:54 +0100