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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - -------------------------------------------------------------------------- CONECTIVA LINUX SECURITY ANNOUNCEMENT - -------------------------------------------------------------------------- PACKAGE : postfix SUMMARY : Remote denial of service vulnerability DATE : 2003-08-04 17:30:00 ID : CLA-2003:717 RELEVANT RELEASES : 7.0, 8 - ------------------------------------------------------------------------- DESCRIPTION Postfix[1] is a widely used MTA (Mail Transport Agent, sometimes called just an email or SMTP server). This update for Conectiva Linux 7.0 and 8 fixes two vulnerabilities in Postfix reported[4] by Michal Zalewski: 1. Postfix used as a bounce scanner (CAN-2003-0468)[2] By using specially created recipients, it is possible to make Postfix attempt to establish SMTP sessions with arbitrary hosts on arbitrary ports. This could be used to identify open TCP ports on remote machines or to just generate traffic. 2. Remote denial of service (CAN-2003-0540)[3] A malformed address can be used to cause a denial of service condition in two ways: - by locking up the queue manager: the offending message has to be manually removed from the queue in order to restore the service; - by locking up the smtpd listener: when supplied with the malformed address, the listener process will stop responding. Multiple attacks in parallel will hang many smtpd processes, leading to a denial of service. In order to be vulnerable to this issue, the "append_dot_mydomain" paramater would have to be changed from the default value of "on" to "off". Conectiva Linux 9 is not vulnerable to any of these issues since it ships with Postfix 2.0.x. SOLUTION All postfix users should upgrade their packages. The service will be automatically restarted after the upgrade if it was already running. REFERENCES 1.http://www.postfix.org/ 2.http://cve.mitre.org/cgi-bin/cvename.cgi?name=2003-0468 3.http://cve.mitre.org/cgi-bin/cvename.cgi?name=2003-0540 4.http://www.securityfocus.com/archive/1/331713/2003-08-01/2003-08-07/0 UPDATED PACKAGES ftp://atualizacoes.conectiva.com.br/7.0/SRPMS/postfix-1.1.13-1U70_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/7.0/RPMS/postfix-1.1.13-1U70_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/7.0/RPMS/postfix-doc-1.1.13-1U70_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/8/SRPMS/postfix-1.1.13-1U80_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/8/RPMS/postfix-1.1.13-1U80_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/8/RPMS/postfix-doc-1.1.13-1U80_1cl.i386.rpm ADDITIONAL INSTRUCTIONS The apt tool can be used to perform RPM packages upgrades: - 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 - ------------------------------------------------------------------------- Copyright (c) 2003 Conectiva Inc. http://www.conectiva.com - ------------------------------------------------------------------------- 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 iD8DBQE/LsuP42jd0JmAcZARAkSUAKCivRAFCAKjTgB6PgvM39MNhNkgxQCfRKSP jPU9/qm3+LBktPbk8OYk3Jg= =19Fy -----END PGP SIGNATURE-----