Remote Exim Exploit In the Wild
An anonymous reader sends word of a remote exploit in the wild against the Exim mail agent. The news comes on the exim mailing list, where a user posted that he had his exim install hacked via remote exploit giving the attacker the privilege of the mailnull user, which can lead to other possible attacks. A note up at the Internet Storm Center reminds exim users how to set up to run in unprivileged mode, and a commenter includes recompile instructions for Debian exim for added safety. The security press hasn't picked up on this story so far.
Welcome to a week ago. Oh, and security guys -are- picking up on it. Stop following companies/press and start following persons.
With Postfix around I see no need for Exim. It's just as lightweight but a lot more powerful and secure.
This isn't FUD. http://www.exim.org/lurker/message/20101209.150448.ee9f5ce6.en.html
http://www.exim.org/lurker/message/20101210.071922.233697ac.en.html
"Paul Fisher and I have successfully run the exploit against a copy of
Exim running in a debugger on debian lenny, and we believe it utilizes
this bug:
http://bugs.exim.org/show_bug.cgi?id=787
It was fixed in 4.70, but not in the version currently in debian
stable.
James E. Blair
UC Berkeley"
It is to the four people who actually succeeded at getting exim to run.
Caveat Utilitor
Because sendmail has such a long record of resistance to security bugs :)
Exim is the MTA that cPanel-enabled servers use, so there is quite a large install base, particularly in the consumer-oriented web hosting space. Except a brief run of ha-ha before the mail spools get moved off to their own partition which is mounted no-exec.
Debian released patches this morning for it.
exim4 (4.69-9+lenny1) stable-security; urgency=high
* Non-maintainer upload by the Security Team.
* Fix SMTP file descriptors being leaked to processes invoked with ${run...}
* Fix memory corruption issue in string_format(). CVE-2010-4344
* Fix potential memory pool corruption issue in internal_lsearch_find().
-- Stefan Fritsch Fri, 10 Dec 2010 13:25:07 +0100
It's a mail server - similar to sendmail etc. Is it really that hard to use google?
I just went digging through my exim install. I have exim-4.72-r1 on Gentoo and it has the fix in it.
it's actually an old bug, the patch is for 4.69 and is from ~2008
"Sir, the email server has a remote exploit!"
"What you say? An exploit?"
"Yeah, exim has a remote hole!"
"Well, it's a good thing we run postfix!"
The greybeard then goes back to smoking his hookah and playing nethack. All is good and right in the world.
More than four people use Debian, where Exim is standard and works out of the box.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
fourth post: "Exim is the MTA..."
if you don't know what an MTA is, sendmail, qmail and postfix are other examples.
“Common sense is not so common.” — Voltaire
Huh? Don't you mean POP3/IMAP server? Because the client is called a "Mail User Agent".
Exim4 doesn't implement POP3/IMAP on its own, you need to set up a separate server to do that, such as Dovecot.
And yes, I specifically suggest using Dovecot.
Yeah but the people who use Debian know they've got it rough enough and don't need to rub it in using Exim.
I use debian. About the first thing I did was disable exim. Why the fuck is it included by default? #fail.
I'd ask you to hand in your geek card, but it appears that you were never issued one to begin with.
The World Wide Web is dying. Soon, we shall have only the Internet.
[... and there goes my karma :( ] .( ], hate blobs. I can do with less functionality if only the software is free. :( ], but I also see good arguments for emacs. SMTP is different: I see no good arguments for neither exim nor sendmail. As much as i like choice, and support the existence of exim and sendmail (and qmail), I have always felt that the distros do a disservice by offering anything else than postfix as default.
Actually, exim was never the thing to do, and yet Debian had it in default.
Just read the archives, and this has been under discussion ever since. OpenBSD has sendmail, likewise, and this has been under discussion ever since.
I am totally a FOSS person [and there goes even more karma
And some perceive postfix as 'not free enough' and so forth. Whatever, relevant is, that exim has always been a dog, almost impossible to configure, and finally with 4.0 changed the style of its configuration. sendmail: just try to understand why you need to install a compiler (m4) to create a configure file? Plus it used to have some security holes several years ago.
In a nutshell, for the last 10 years, being on Debian, OpenBSD or whatnot, the first thing to go in all my boxes is any not-postfix MTA, and postfix to come thereafter.
Yes, I'm a vi person [OMG, all karma negative!
[citation needed]
--
DUH!
I use Exim. I have great clanking balls.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
Welcome to the early 1990's of memory debugging.
That string_format problem is incredibly shameful this day and age, too.
You know what? I think I'm going to run my exim4 installation under Valgrind, set to terminate at the first memory error.
(Will I still get any e-mail?)
So that mail can be delivered...?
I don't really get all the hate for Exim. I've been using it exclusively on mail servers for about 10 years, and I've never had a problem. I do remember going through a lot of reading and learning (and sometimes experimenting) the first few times I set it up (and of course when implementing a major feature change). But, for me, the task was less daunting than the alternatives. I don't really remember whether postfix was one of those alternatives I explored at the time, but now that I'm familiar with Exim, I see no reason to change.
"Somebody has to do something. It's just incredibly pathetic it has to be us."
--- Jerry Garcia
It wouldn't kill you not to be a complete idiot and note the word 'MTA' and/or use google. We can only assume.
[0]
1. Try it
2. It works.
3. Profit???
Huh? Don't you mean POP3/IMAP server? Because the client is called a "Mail User Agent".
But a POP3/IMAP server is rather an MDA. An SMTP server is an MTA.
note the word 'MTA' and/or use google
Give me a break, I actually checked the first cited article (of the 3) and googled “mail agent” before I gave up and just asked.
Distributed Denial of APK: It takes 15 seconds to reply to him anonymously, but wastes tons of his time if we all do it.
My computer isn't a mail server. Why does it need to deliver mail? Pros: none. Cons: uses memory, uses cpu, and it's a nice fat exploit vector.
And you little scanner too!
Cron job outputs, for one.
POP3 and IMAP servers are not MDA's.
They don't "deliver" anything, and that is what the D in MDA is for.
Procmail, mail.local, deliver, etc are MDA's.
Whereas Exim doesn't *need* milters because it's sufficiently capable all by itself.
I once had a Postfix advocate look over my Exim config to see if he make Postfix do what Exim can do. He gave up.
Cron job outputs, for one.
Yeah; a real Unix system has a mail daemon; too many things break if it doesn't. Although *if* I use exim, I let the Debian installer configure it for local mail delivery only. For mail servers which actually have to speak SMTP, I choose postfix (which is one well-supported alternative in Debian).
Bet you never thought you'd read that in response to a security announcement. :)
Is exim supposed to be difficult? Damn. Maybe I'm better than I thought (unlikely) or you're lamer than you think (ref. Dunning-Kruger Effect.)
Whichever.
Lacking <sarcasm> tags,
... fixed that for you.
"... Nobody DARES to even try!" -> http://yro.slashdot.org/comments.pl?sid=1903798&cid=34515054 you "ran away" over there at the URL icebraining... why is that? LMAO!
("You try to catch me, but you-just-can't-catch-a-hurricane!")
APK
P.S.=> As to my subject-line above and how it pertains to that link above & our discussion on HOSTS files (where I completely BLEW YOU AWAY, lol)? See THE RODS' video here -> http://www.youtube.com/watch?v=apOdWOK5Rh8&feature=related ... apk
The parent conjured up "Exim haters" out of thin air, but it's really a fiction. There is nothing that warrants such a label.
Sure, we all have our own preferences for MTAs, and we even complain occasionally about particular features or unhelpful config styles, but that's the same for all applications. Sendmail's config is of course a joke, but that's an old MTA and shouldn't be compared with any of the modern ones like Exim, qmail, Postfix, etc.
All MTAs have their proponents, but "MTA haters" really don't exist as a sizeable group for any modern FOSS MTA, beyond a few colorful characters who claim that only their own code is any good.
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra