From secure@conectiva.com.br Mon Jun 25 01:34:07 2001 From: secure@conectiva.com.br To: conectiva-updates@papaleguas.conectiva.com.br, linuxlist@securityportal.com, lwn@lwn.net, bugtraq@securityfocus.com Date: Sat, 23 Jun 2001 20:33:35 -0300 Subject: [CLA-2001:405] Conectiva Linux Security Announcement - samba -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - -------------------------------------------------------------------------- CONECTIVA LINUX SECURITY ANNOUNCEMENT - -------------------------------------------------------------------------- PACKAGE : samba SUMMARY : Remote root vulnerability DATE : 2001-06-23 19:55:00 ID : CLA-2001:405 RELEVANT RELEASES : 4.0, 4.0es, 4.1, 4.2, 5.0, prg graficos, ecommerce, 5.1, 6.0 - ------------------------------------------------------------------------- DESCRIPTION "samba" is a server that provides SMB services such as file and printer sharing for other SMB clients, such as Windows(R). Michal Zalewski reported a remote vulnerability that could be used to gain root privileges on the samba server. A remote attacker can set the NetBIOS name of his machine to almost any name. This string will be used in place of "%m" in the /etc/smb.conf configuration file. This can be used to append data that is under the attacker's control to any file on the system depending on how the "%m" macro is used. The published exploit relies on the "log file" directive as found in some configurations: log file = /var/log/samba/%m.log An attacker could abuse this configuration, which is *not* the default on Conectiva Linux, and set, for example, "../../../tmp/x" as his NetBIOS name. This would trick samba into appending data to a "/tmp/x.log" file. If this file is a symbolic link, it will be followed. There is a limit of 16 characters for the NetBIOS name, so most attacks would probably rely on a symbolic link in /tmp or, if the "%m" macro is used alone (such as "/var/log/samba/%m"), then any file in a directory close to root (such as /bin/ls). The default configuration of "log file" in Conectiva Linux does not allow this kind of attack: log file = /var/log/samba/log.%m SOLUTION All samba users should upgrade their packages immediately. In the meantime, administrators should check their /etc/smb.conf configuration file for "%m" and either substitute this macro or remove it until the update can be applied. This update will automatically restart the samba service if it's already running. REFERENCES: 1. http://us1.samba.org/samba/whatsnew/macroexploit.html DIRECT DOWNLOAD LINKS TO THE UPDATED PACKAGES ftp://atualizacoes.conectiva.com.br/4.0/SRPMS/samba-2.0.9-2U40_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/4.0/i386/samba-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0/i386/samba-clients-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0/i386/samba-doc-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0/i386/samba-swat-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0es/SRPMS/samba-2.0.9-2U40_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/4.0es/i386/samba-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0es/i386/samba-clients-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0es/i386/samba-doc-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.0es/i386/samba-swat-2.0.9-2U40_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.1/SRPMS/samba-2.0.9-2U41_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/4.1/i386/samba-2.0.9-2U41_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.1/i386/samba-clients-2.0.9-2U41_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.1/i386/samba-doc-2.0.9-2U41_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.1/i386/samba-swat-2.0.9-2U41_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.2/SRPMS/samba-2.0.9-2U42_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/4.2/i386/samba-2.0.9-2U42_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.2/i386/samba-clients-2.0.9-2U42_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.2/i386/samba-doc-2.0.9-2U42_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/4.2/i386/samba-swat-2.0.9-2U42_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.0/SRPMS/samba-2.0.9-2U50_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/5.0/i386/samba-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.0/i386/samba-clients-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.0/i386/samba-doc-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.0/i386/samba-swat-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.1/SRPMS/samba-2.0.9-2U51_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/5.1/i386/samba-2.0.9-2U51_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.1/i386/samba-clients-2.0.9-2U51_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.1/i386/samba-doc-2.0.9-2U51_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/5.1/i386/samba-swat-2.0.9-2U51_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/6.0/SRPMS/samba-2.0.9-2U60_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/6.0/RPMS/samba-2.0.9-2U60_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/6.0/RPMS/samba-clients-2.0.9-2U60_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/6.0/RPMS/samba-doc-2.0.9-2U60_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/6.0/RPMS/samba-swat-2.0.9-2U60_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/SRPMS/samba-2.0.9-2U50_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/samba-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/samba-clients-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/samba-doc-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/samba-swat-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/SRPMS/samba-2.0.9-2U50_1cl.src.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/samba-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/samba-clients-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/samba-doc-2.0.9-2U50_1cl.i386.rpm ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/samba-swat-2.0.9-2U50_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 v1.0.4 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE7NSdO42jd0JmAcZARApeXAJ0XS2T/yw0Zan5cVz5zkbdg3y6sDQCgya1L mmgeEPW8ez7jpvY8CVAVUqU= =3Ysh -----END PGP SIGNATURE-----