AUSCERT External Security Bulletin Redistribution
                      ESB-2000.065 -- FreeBSD-SA-00:11
                    ircII port contains a remote overflow
                                11 April 2000


The FreeBSD Security Team has released the following advisory concerning a
vulnerability in ircii's dcc chat capability. This vulnerability may allow
a remote user to execute code as the user of the ircii client.

This is the same vulnerability as previously described in AUSCERT External
Security Bulletin ESB-2000.060.

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FreeBSD-SA-00:11                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:		ircII port contains a remote overflow

Category:       ports
Module:         ircII
Announced:      2000-04-10
Credits:	Derek Callaway <super@UDEL.EDU> via BugTraq
		"bladi" <bladi@EUSKALNET.NET> via BugTraq
Affects:        Ports collection before the correction date.
Corrected:      2000-03-19
FreeBSD only:   NO

I.   Background

ircII is a popular text-mode IRC client.

II.  Problem Description

ircII version 4.4 contained a remotely-exploitable buffer overflow in
the /DCC CHAT command which allows remote users to execute arbitrary
code as the client user.

The bug was originally reported in 1997 in a much older version of
ircII, but was apparently not corrected at the time, and the problem
was recently rediscovered independently. Development on the version of
ircII previously in ports ceased several years ago, and has been taken
up by a new group who have fixed this problem (and possibly
others). FreeBSD now provides this new version of ircII.

The ircII port is not installed by default, nor is it "part of
FreeBSD" as such: it is part of the FreeBSD ports collection, which
contains over 3200 third-party applications in a ready-to-install
format. FreeBSD 4.0 did not ship with the ircII package available
because this vulnerability was reported to us late in the release
cycle and it was not possible to upgrade the port in time.

FreeBSD makes no claim about the security of these third-party
applications, although an effort is underway to provide a security
audit of the most security-critical ports.

III. Impact

A remote user can cause arbitrary code to be executed on the local
system as the user running ircII.

If you have not chosen to install the ircII port/package, then your
system is not known to be vulnerable to this problem, although there
are several other IRC clients which are derived from ircII including
Epic and BitchX. At this time it is unknown whether other clients are
vulnerable to this problem.

IV.  Workaround

Remove the ircII port, if you you have installed it.

V.   Solution

1) Upgrade your entire ports collection and rebuild the ircII port.

2) Reinstall a new package dated after the correction date, obtained from:


3) download a new port skeleton for the ircII port from:


and use it to rebuild the port.

4) Use the portcheckout utility to automate option (3) above. The
portcheckout port is available in /usr/ports/devel/portcheckout or the
package can be obtained from:


Version: 2.6.2


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