Mandrake Linux Security Advisory : openssh (MDKSA-2006:034)
Medium Nessus Plugin ID 20875
SynopsisThe remote Mandrake Linux host is missing one or more security updates.
DescriptionA flaw was discovered in the scp local-to-local copy implementation where filenames that contain shell metacharacters or spaces are expanded twice, which could lead to the execution of arbitrary commands if a local user could be tricked into a scp'ing a specially crafted filename.
The provided updates bump the OpenSSH version to the latest release version of 4.3p1. A number of differences exist, primarily dealing with PAM authentication over the version included in Corporate 3.0 and MNF2. In particular, the default sshd_config now only accepts protocol 2 connections and UsePAM is now disabled by default.
On systems using alternate authentication methods (ie. LDAP) that use the PAM stack for authentication, you will need to enable UsePAM. Note that the default /etc/pam.d/sshd file has also been modified to use the pam_listfile.so module which will deny access to any users listed in /etc/ssh/denyusers (by default, this is only the root user). This is required to preserve the expected behaviour when using 'PermitRootLogin without-password'; otherwise it would still be possible to obtain a login prompt and login without using keys.
Mandriva Linux 10.1 and newer already have these changes in their shipped versions. There are new features in OpenSSH and users are encouraged to review the new sshd_config and ssh_config files when upgrading.
SolutionUpdate the affected packages.