Conectiva: “ISS published an advisory concerning a remote vulnerability in OpenSSH that could be used by remote attackers to obtain root privileges on the server where OpenSSH is running… To minimize the impact of this vulnerability the 3.3p1 version of OpenSSH has been made available previously. That version, which still has this vulnerability, implements by default the PrivilegeSeparation mechanism which greatly reduces the impact of this and potential future vulnerabilities in OpenSSH.”
- -------------------------------------------------------------------------- CONECTIVA LINUX SECURITY ANNOUNCEMENT - -------------------------------------------------------------------------- PACKAGE : openssh SUMMARY : Remote vulnerability in openssh DATE : 2002-06-28 15:27:00 ID : CLA-2002:502 RELEVANT RELEASES : 6.0, 7.0, 8 - ------------------------------------------------------------------------- DESCRIPTION OpenSSH[1] is a very popular and versatile tool that uses encrypted connections between hosts and is commonly used for remote administration. ISS[5] published[4] an advisory concerning a remote vulnerability in OpenSSH that could be used by remote attackers to obtain root privileges on the server where OpenSSH is running. The vulnerability is present in two authentication mechanisms: ChallengeResponse and PAMAuthenticationViaKbdInt. If these mechanisms are not necessary in your installation, they can be disabled by the following entries in /etc/ssh/sshd_config: ChallengeResponseAuthentication no PAMAuthenticationViaKbdInt no Please note that any changes made to the sshd_config file require a service restart to be effective. To minimize the impact of this vulnerability the 3.3p1 version of OpenSSH has been made available previously[2]. That version, which still has this vulnerability, implements by default the PrivilegeSeparation mechanism which greatly reduces the impact of this and potential future vulnerabilities in OpenSSH. The 3.4p1 version of OpenSSH has now been made available and it includes fixes for the reported vulnerabilities. Even though the vulnerability is fixed in version 3.4p1, users are still advised to keep using the PrivilegeSeparation feature. There are, though, still a few problems with certain authentication methods and PrivilegeSeparation that are expected to be solved in future releases. Whenever appropriate, new packages will be provided as bugfix advisories. In particular, the packages provided here contain a patch from Solar Designer (from the Openwall Project[4]) which allows the use of PrivilegeSeparation together with data compression in 2.2 kernels. Next releases might not need this patch anymore. If for some reason the use of PrivilegeSeparation is not possible in some setup, it can be disabled via the following entry in /etc/ssh/sshd_config: UsePrivilegeSeparation no SOLUTION It is recommended that all OpenSSH users upgrade their packages. The ssh service will be automatically restarted during the upgrade if it is already running. Current ssh sessions will remain open during the restart. REFERENCES 1.http://www.openssh.com 2.http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000500 3.http://www.cert.org/advisories/CA-2002-18.html 4.http://bvlive01.iss.net/issEn/delivery/xforce/alertdetail.jsp?oid=20584 5.http://www.iss.net/ 6.http://www.openwall.com/Owl/ DIRECT DOWNLOAD LINKS TO THE UPDATED PACKAGES ftp://atualizacoes.conectiva.com.br/6.0/SRPMS/openssh-3.4p1-1U60_1cl.src.rpmftp://atualizacoes.conectiva.com.br/6.0/RPMS/openssh-3.4p1-1U60_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/6.0/RPMS/openssh-askpass-3.4p1-1U60_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/6.0/RPMS/openssh-askpass-gnome-3.4p1-1U60_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/6.0/RPMS/openssh-clients-3.4p1-1U60_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/6.0/RPMS/openssh-server-3.4p1-1U60_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/7.0/SRPMS/openssh-3.4p1-1U70_1cl.src.rpmftp://atualizacoes.conectiva.com.br/7.0/RPMS/openssh-3.4p1-1U70_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/7.0/RPMS/openssh-askpass-3.4p1-1U70_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/7.0/RPMS/openssh-askpass-gnome-3.4p1-1U70_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/7.0/RPMS/openssh-clients-3.4p1-1U70_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/7.0/RPMS/openssh-server-3.4p1-1U70_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/8/SRPMS/openssh-3.4p1-1U8_1cl.src.rpmftp://atualizacoes.conectiva.com.br/8/RPMS/openssh-3.4p1-1U8_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/8/RPMS/openssh-askpass-3.4p1-1U8_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/8/RPMS/openssh-askpass-gnome-3.4p1-1U8_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/8/RPMS/openssh-clients-3.4p1-1U8_1cl.i386.rpmftp://atualizacoes.conectiva.com.br/8/RPMS/openssh-server-3.4p1-1U8_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
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