From secure@conectiva.com.br Wed Nov 20 23:07:55 2002 From: secure@conectiva.com.br To: conectiva-updates@papaleguas.conectiva.com.br, lwn@lwn.net, bugtraq@securityfocus.com, security-alerts@linuxsecurity.com Date: Mon, 18 Nov 2002 19:28:30 -0200 Subject: [CLA-2002:549] Conectiva Linux Security Announcement - dhcpcd -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - -------------------------------------------------------------------------- CONECTIVA LINUX SECURITY ANNOUNCEMENT - -------------------------------------------------------------------------- PACKAGE : dhcpcd SUMMARY : Characters expansion vulnerability DATE : 2002-11-18 19:28:00 ID : CLA-2002:549 RELEVANT RELEASES : 6.0, 7.0, 8 - ------------------------------------------------------------------------- DESCRIPTION dhcpcd is an RFC2131 and RFC1541 compliant DHCP client daemon. dhcpcd has the ability to execute an external script named /sbin/dhcpcd-.exe when assigning a new IP address to a network interface. This script sources a file named /var/lib/dhcpcd/dhcpcd-.info that contains several shell variables and assigments with DHCP information. Simon Kelley pointed out a vulnerability in the way quotes inside these assignments are treated. By exploiting this, a malicious DHCP server (or attackers able to spoof DHCP responses) can execute arbitrary shell commands on the DHCP client (which is run by root). The script /sbin/dhcpcd-.exe is not installed by default in Conectiva Linux, but is included in the documentation directory of the dhcpcd package. Please notice that it is possible to exploit this vulnerability only if the user has installed the script manually. SOLUTION All dhcpcd users are advised to upgrade. IMPORTANT NOTE: After the upgrade, dhcpcd must be restarted manually. This can be accomplished by the command: # service network restart Please be careful if doing this remotely, since this will shutdown and restart the network interfaces and potentially change their IP address. REFERENCES: 1.http://www.phystech.com/download/dhcpcd_changelog.html DIRECT DOWNLOAD LINKS TO THE UPDATED PACKAGES ftp://atualizacoes.conectiva.com.br/6.0/RPMS/dhcpcd-1.3.22pl3-1U60_2cl.i386.rpm ftp://atualizacoes.conectiva.com.br/6.0/SRPMS/dhcpcd-1.3.22pl3-1U60_2cl.src.rpm ftp://atualizacoes.conectiva.com.br/7.0/RPMS/dhcpcd-1.3.22pl3-1U70_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/7.0/SRPMS/dhcpcd-1.3.22pl3-1U70_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/8/RPMS/dhcpcd-1.3.22pl3-1U80_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/8/SRPMS/dhcpcd-1.3.22pl3-1U80_1cl.src.rpm ADDITIONAL INSTRUCTIONS Users of Conectiva Linux version 6.0 or higher may use apt to perform upgrades of RPM packages: - add the following line to /etc/apt/sources.list if it is not there yet (you may also use linuxconf to do this): rpm [cncbr] ftp://atualizacoes.conectiva.com.br 6.0/conectiva updates (replace 6.0 with the correct version number if you are not running CL6.0) - run: apt-get update - after that, execute: apt-get upgrade Detailed instructions reagarding the use of apt and upgrade examples can be found at http://distro.conectiva.com.br/atualizacoes/#apt?idioma=en - ------------------------------------------------------------------------- All packages are signed with Conectiva's GPG key. The key and instructions on how to import it can be found at http://distro.conectiva.com.br/seguranca/chave/?idioma=en Instructions on how to check the signatures of the RPM packages can be found at http://distro.conectiva.com.br/seguranca/politica/?idioma=en - ------------------------------------------------------------------------- All our advisories and generic update instructions can be viewed at http://distro.conectiva.com.br/atualizacoes/?idioma=en - ------------------------------------------------------------------------- subscribe: conectiva-updates-subscribe@papaleguas.conectiva.com.br unsubscribe: conectiva-updates-unsubscribe@papaleguas.conectiva.com.br -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE92Vt842jd0JmAcZARAl/FAKDsbtwiqyi0OY5oyhhvjWLTFWGnMACeICPC s9ZlCJqhjszCMyRNtUE8aTU= =1YUu -----END PGP SIGNATURE-----