From secure@conectiva.com.br Thu May 9 23:39:56 2002 From: secure@conectiva.com.br To: conectiva-updates@papaleguas.conectiva.com.br, lwn@lwn.net, bugtraq@securityfocus.com, security-alerts@linuxsecurity.com Date: Thu, 9 May 2002 11:53:28 -0300 Subject: [CLA-2002:483] Conectiva Linux Security Announcement - dhcp -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - -------------------------------------------------------------------------- CONECTIVA LINUX SECURITY ANNOUNCEMENT - -------------------------------------------------------------------------- PACKAGE : dhcp SUMMARY : Format string vulnerability DATE : 2002-05-09 11:52:00 ID : CLA-2002:483 RELEVANT RELEASES : 8 - ------------------------------------------------------------------------- DESCRIPTION "dhcp" is a Dynamic Host Configuration Protocol Server and Client. Versions ranging from 3 to 3.0.1rc8 (inclusive) have a format string vulnerability[1] that could be exploited remotely. Considering the usage of the DHCP service, this usually means the local area network in this case. By default, these versions of DHCP are compiled with the dns update feature enabled. This feature allows the DHCP service to update dns records. The code in DHCP that logs this update has a format string vulnerability that could be exploited, since the update message contains data provided by the attacker, such as a hostname. A successful exploitation would give an attacker the same privileges the DHCP daemon has, tipically root. This vulnerability was discovered and researched by Fermín J. Serna from Next Generation Security Technologies[2] and published in coordination with CERT. SOLUTION All dhcp users should upgrade immediately. After upgrading the packages, manually restart the dhcp server with the following command: service dhcpd restart REFERENCES 1. http://www.cert.org/advisories/CA-2002-12.html 2. http://www.ngsec.com/docs/advisories/NGSEC-2002-2.txt 3. http://www.isc.org/ DIRECT DOWNLOAD LINKS TO THE UPDATED PACKAGES ftp://atualizacoes.conectiva.com.br/8/SRPMS/dhcp-3.0-3U8_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/8/RPMS/dhcp-3.0-3U8_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/8/RPMS/dhcp-doc-3.0-3U8_1cl.i386.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 iD8DBQE82o1n42jd0JmAcZARAjtjAKDGFkFx5SijaFZF4Dkb59QapWnOqwCg4ukN NsnGBgY8auRqNJUZgRsROjE= =SJxg -----END PGP SIGNATURE-----