LinuxQuestions.org
Download your favorite Linux distribution at LQ ISO.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Security
User Name
Password
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.

Notices



Closed Thread
 
Search this Thread
Old 01-18-2002, 12:47 PM   #46
unSpawn
Moderator
 
Registered: May 2001
Posts: 27,744
Blog Entries: 54

Rep: Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973Reputation: 2973

Ok. Here's what I found.
I even installed qpop myself to be sure I wouldn't be taken out into the field, etc, etc :-]
The sendmail part will be allright. There's no doubt about that. (Keep yer eyes on the money) Running as a (severely) underprivileged user will lose you some functionality, but if all apps run by that user are not $UID == 0, the only user (say in case of BO (not body odour, heh)) they will end up as will be the $UID of that underprivileged user.
Now unfortunately Qpop will not have this; a user sends mail off to another user. This will have sendmail either defer to mqueue (say due to host unreachable), or gets mailed by the local mailer (LDA, say procmail) to a local user's spool (mail) or is sent right away by sendmail.
No probs to this point.

Now the user accesses pine to read local mail, this is loaded from the mailspool (/var/spool/mail/$UID, with $UID=$UID and $GID=mail). No problem here.

Now the user accesses :110 to read mail.
When Popper is started from (x)inetd (as root) it will (fork() and) change $UID and $GID to the connecting user to read mail.
But when popper is started by an underprivileged user, presto, there's no way popper *can* change $UID and $GID to the users' mailspool.
RTFM'ing Qpop's docs I came to the conclusion this pop3 server does not have any way to safely work with an $UID != 0, I can't find any option so it would only have to change $GID and work with that.

/* Alas, thus endeth this thread in the valley of Death, after exactly 9 days worth of 'em...
Was definately fun working with you on this one, even tho we didn't accomplish all goals.

Cheers, unSpawn
*/
 
  


Closed Thread


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to make Sendmail forward all incoming mail to localhost port 26 (Domino mail) speedgelb Linux - Software 3 09-27-2013 11:18 AM
sendmail error Fetching mail could not lock /var/spool/mail/username sukhdev50 Linux - Networking 0 05-04-2005 04:41 AM
How to Attach files using 'Mail' or 'SendMail' Harlin Linux - Networking 2 02-19-2005 09:48 AM
Change sendmail by lotus domino for root mail cgillard Linux - Networking 1 06-16-2004 03:33 AM
Sendmail Error while sendmail mail palavsachin27 Linux - Networking 1 01-22-2003 05:14 PM


All times are GMT -5. The time now is 05:10 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration