COMMAND
fsh
SYSTEMS AFFECTED
fsh
PROBLEM
Following is based on a Debian Security Advisory DSA-002-1.
Colin Phipps found an interesting symlink attack problem in fsh (a
tool to quickly run remote commands over rsh/ssh/lsh). When fshd
starts it creates a directory in /tmp to hold its sockets. It
tries to do that securely by checking of it can chown that
directory if it already exists to check if it is owner by the
user invoking it. However an attacker can circumvent this check
by inserting a symlink to a file that is owner by the user who
runs fhsd and replacing that with a directory just before fshd
creates the socket.
SOLUTION
For Debian:
http://security.debian.org/dists/stable/updates/main/source/fsh_1.0.post.1-3potato.diff.gz
http://security.debian.org/dists/stable/updates/main/source/fsh_1.0.post.1-3potato.dsc
http://security.debian.org/dists/stable/updates/main/source/fsh_1.0.post.1.orig.tar.gz
http://security.debian.org/dists/stable/updates/main/binary-alpha/fsh_1.0.post.1-3potato_alpha.deb
http://security.debian.org/dists/stable/updates/main/binary-arm/fsh_1.0.post.1-3potato_arm.deb
http://security.debian.org/dists/stable/updates/main/binary-i386/fsh_1.0.post.1-3potato_i386.deb
http://security.debian.org/dists/stable/updates/main/binary-m68k/fsh_1.0.post.1-3potato_m68k.deb
http://security.debian.org/dists/stable/updates/main/binary-powerpc/fsh_1.0.post.1-3potato_powerpc.deb
http://security.debian.org/dists/stable/updates/main/binary-sparc/fsh_1.0.post.1-3potato_sparc.deb