AW: [ISN] Majordomo Could Mean Major Spam
From: Meidinger Chris (chris.meidinger_at_badenit.de)
Date: 09/08/03
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To: 'Jay Woody' <jay_woody@tnb.com>, security-basics@securityfocus.com Date: Mon, 8 Sep 2003 19:21:14 +0100
i'm pretty sure security basics uses ezmlm and not majordomo. could be wrong
though.
-chris
-----Ursprüngliche Nachricht-----
Von: Jay Woody [mailto:jay_woody@tnb.com]
Gesendet: Montag, 8. September 2003 16:57
An: security-basics@securityfocus.com
Betreff: Fwd: [ISN] Majordomo Could Mean Major Spam
Seems like every other week, someone sends a note to a list I am on that
says, "I don't use this account for anything but lists and now it is getting
spam." This may be why. If you are running a list using majordomo, here is
some info you may want to be aware of.
JayW
>>> InfoSec News <isn@c4i.org> 09/08/03 12:20AM >>>
http://www.pc-radio.com/majordomo.html
By Brian McWilliams
PC-Radio.com
September 7, 2003
Getting lots of spam? Perhaps Majordomo is partly to blame.
Numerous high-profile sites running the free Majordomo mailing list
server are vulnerable to an "information leakage" attack first
reported nearly a decade ago.
The technique allows anyone to grab a list of subscriber addresses
using a little-known but documented feature in the Majordomo server
software.
A quick survey easily turned up dozens of e-mail lists ripe for
harvesting by the technique, which involves sending a standard command
to a Majordomo server via e-mail. Among the vulnerable list operators
were government, military, commercial, and educational organizations.
The Majordomo "which" command was originally designed to allow list
administrators and subscribers to see who is on a mailing list.
But the technique could also enable spammers to collect addresses that
are effectively unpublished and not previously available through
current spam extraction tools.
"This bug could be used by evil spammers to fill their databases,"
wrote security researcher Marco van Berkum in an advisory published
last February about the potential privacy problem. Barkum rated the
vulnerability "high" impact.
Over 12,000 e-mails, most of them ending in "dot-gov" amd "dot-mil"
were easily accessible by sending the "which" command in an e-mail to
a Majordomo server operated by the National Aeronautics and Space
Administration. Addresses were organized according to list topics,
such as "code-w-investigators" and "nasa-dcfos-finance." NASA
officials disabled the command after being alerted to the spam threat
this week.
Even some information technology-savvy companies were susceptible to
the collection technique. A West-coast Internet service provider's
open Majordomo server provided over 150,000 e-mails in response to the
command. A Majordomo server hosted by a large computer networking
manufacturer responded to "which" commands by returning a list of more
than 43,000 e-mail addresses of customers and other Internet users.
Neither firm acknowledged warnings about the e-mail harvesting threat.
Sun Microsystems offered up more than 6,500 e-mail addresses of
Internet users who had subscribed to discussion lists dedicated to a
variety of technology topics. After Sun was notified about the
vulnerability, the company's Majordomo server was unreachable Friday.
According to Brent Chapman, founder of Great Circle Associates, which
created Majordomo in 1992, the "which" feature was developed at a time
when programmers "were far less concerned about spammers harvesting
e-mail addresses than people are today."
By default, installations of Majordomo version 1 are configured to
accept the "which" command. An independently developed successor,
Majordomo 2, is not vulnerable to the extraction technique.
While some administrators may leave the feature enabled on purpose,
many appear unaware of the potential vulnerability in Majordomo, which
is currently in use at "several hundred thousand" sites, according to
Chapman.
At present, junk e-mailers rely primarily on mailing lists compiled by
automated tools that extract e-mail addresses from public Web pages
and Usenet discussion groups. The resulting lists are typically sorted
into broad categories, such as "AOL" or "Hotmail" or "global
Internet."
Universities typically protect their online directories from such data
collection by spammers, yet Majordomo installations at several higher
education institutions allowed open access via the "which" command. A
list of nearly 33,000 e-mail addresses was available from a large
eastern university's Majordomo server. Some 14,500 e-mail addresses
were available from an Ivy League college's server. Computing
administrators at the two institutions did not immediately respond to
warnings about the potential problems.
Chapman said he first became aware of Majordomo's potential security
flaw in 1993. In 1996 he published instructions on a mailing list for
Majordomo administrators about how to disable the feature. However,
the potential problems raised by the "which" command are not mentioned
in the documentation currently included with the software.
In 1999 a Majordomo user reported that the default installation of the
software allows list subscribers to be extracted, and noted that
"several" installations were vulnerable.
Great Circle discontinued development of Majordomo with version 1.94.5
in 2000 and no longer supports the software, although the company
continues to distribute it for free as a public service, Chapman said.
By examining e-mail message headers for the term "Majordomo," list
subscribers may be able to identify whether their discussions are
being hosted by a Majordomo server. Administrators of the server can
often be reached via the user name " Majordomo-owner@" followed by the
server's address.
-
ISN is currently hosted by Attrition.org
To unsubscribe email majordomo@attrition.org with 'unsubscribe isn' in the
BODY of the mail.
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---------------------------------------------------------------------------
Captus Networks
Are you prepared for the next Sobig & Blaster?
- Instantly Stop DoS/DDoS Attacks, Worms & Port Scans
- Precisely Define and Implement Network Security
- Automatically Control P2P, IM and Spam Traffic
FIND OUT NOW - FREE Vulnerability Assessment Toolkit
http://www.captusnetworks.com/ads/42.htm
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