bugSpamAssassin Milter Plugin - Bugs: bug #14731, -x without -e has a security risk

 
 

bug #14731: -x without -e has a security risk

Submitted by:  None
Submitted on:  Thu 06 Oct 2005 05:58:56 AM UTC  
 
Category: NoneSeverity: 3 - Normal
Item Group: NoneStatus: None
Privacy: PublicAssigned to: Dan Nelson <dnelson>
Open/Closed: Open

Add a New Comment (Rich MarkupRich Markup):
   

You are not logged in

Please log in, so followups can be emailed to you.

 

Thu 06 Oct 2005 05:58:56 AM UTC, original submission:

When configured with "-u nobody -x" and not using -e, outgoing or mail sent though the server could be intercepted by another user.

spamass-milter[17342]: calling /usr/lib/sendmail -bv "<Test@test.com>" 2>&1
spamass-milter[17342]: sendmail output: <test@test.com>... deliverable: mailer esmtp, host test.net., user -unavailable-
spamass-milter[17342]: user: -unavailable-
spamass-milter[17342]: Total of 1 actual recipients
spamass-milter[17342]: remembering -unavailable- for spamc
spamass-milter[17342]: remembering recipient <test@test.com>

spamass-milter[21108]: spamc gets test2
spamd[15262]: connection from localhost.localdomain [127.0.0.1] at port 35697
spamd[15262]: info: setuid to test2 succeeded
spamd[15262]: processing message <di277llv+5d1n@eGroups.com> for test:533.

spamc now uses "test2" user_prefs file that neither the sender nor the rcpt have access to. Third party user "test2" then could configure there user_prefs to resend that mail to him/herself or do a number of tricks one could do in the user_prefs

Using "-i" with the local server IP can prevent mail sent though the server from being process by spamc, but forwarded mail is still at risk.

Sujested soluction, look at the "mailer" field of the sendmail output, in this case, its "esmtp" meaning forward that mail to the next server or send that mail to the server if it was generated locally. Look for the "mailer local" responce to send the user to spamc, anything else, send the -u preference to spamc. Note that the mailmam program will give these results:

sendmail -bv -unavailable-
"|/var/mailman/mail/mailman post test-annoucementandart"... deliverable: mailer prog, user "|/var/mailman/mail/mailman post test-annoucementandart"

spamd[15262]: handle_user: unable to find user '"|/var/mailman/mail/mailman post test-annoucementandart"'!

In this case, "|/var/mailman/mail/mailman post test-annoucementandart" is send to spamc, including the quotes. Luckfully, it doesn't crash on that bad username input.

This is why I sujest looking for "local" and rejecting anything else as non-local user and use "-u" preference to send to spamc.

Anonymous

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach File(s):
   
   
Comment:
   

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

CC list is empty

 

Do you think this task is very important?
If so, you can click here to add your encouragement to it.
This task has 0 encouragements so far.

Only logged-in users can vote.

 

Please enter the title of George Orwell's famous dystopian book (it's a date):

 

 

Follows 1 latest change.

Date Changed By Updated Field Previous Value => Replaced By
Thu 06 Oct 2005 06:10:46 AM UTCdnelsonAssigned toNone=>dnelson

Back to the top


Powered by Savane 3.1-cleanup