-----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-00:57 Security Advisory FreeBSD, Inc. Topic: muh IRC bouncer remote vulnerability Category: ports Module: muh Announced: 2000-10-13 Credits: Maxime Henrion Affects: Ports collection prior to the correction date. Corrected: 2000-09-10 (4.1.1-RELEASE) Vendor status: Updated version released FreeBSD only: NO I. Background muh is an IRC bouncer, a program that allows a host to act as a relay between an IRC client on a local/remote machine and the IRC server. II. Problem Description The muh port, versions 2.05c and before, contains a vulnerability which allows remote users to gain the privileges of the user running muh. This is accomplished by sending a carefully crafted exploit string containing string format operators to a user using muh but who is not connected. When the user reconnects and executes '/muh read', muh will allow the remote attacker to execute arbitrary code as the local user. The muh port is not installed by default, nor is it "part of FreeBSD" as such: it is part of the FreeBSD ports collection, which contains nearly 4000 third-party applications in a ready-to-install format. The ports collections shipped with FreeBSD 3.5.1 and 4.1 contain this problem since it was discovered after the releases, but it was corrected prior to the release of FreeBSD 4.1.1. 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 Remote IRC users can cause arbitrary code to be executed as the user running muh. If you have not chosen to install the muh port/package, then your system is not vulnerable to this problem. IV. Workaround Deinstall the muh port/package, if you you have installed it. V. Solution One of the following: 1) Upgrade your entire ports collection and rebuild the muh port. 2) Deinstall the old package and install a new package dated after the correction date, obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/irc/muh-2.05c.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/irc/muh-2.05c.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/irc/muh-2.05c.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/irc/muh-2.05c.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/irc/muh-2.05c.tgz NOTE: It may be several days before updated packages are available. 3) download a new port skeleton for the cvsweb port from: http://www.freebsd.org/ports/ 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: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/devel/portcheckout-2.0.tgz -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBOebDhVUuHi5z0oilAQE/3wP+K6oPSZ4jsnLAILhZD3fjdp+3bW7IhDmQ PoXpqSyEypJ6TlP0wLaZwhz1VPThAN9yVaUTzA7W8MVQyKCdIDBWu86WmcZ4CsY9 v7ku77tshEcxza+ggegy9PkSWYDfaQIyGzRyZht280qxn5XUFIeEvXkx+YHKvffo Rm4dlo/akzA= =0bP+ -----END PGP SIGNATURE-----