Hi again, I'm sorry, my previous patch didn't check mktemp's return value, and if mktemp fails, DIR is empty and [ -d $DIR ] succeeds (for whatever reason). So this is still exploitable if fbgs is executed in a dir the attacker has write access to.
Attached a new version which might be correct. :/ Jan
diff -ru fbida-2.01.orig/fbgs fbida-2.01/fbgs --- fbida-2.01.orig/fbgs 2004-03-28 13:32:16.000000000 +0200 +++ fbida-2.01/fbgs 2006-04-08 02:49:37.000000000 +0200 @@ -1,8 +1,8 @@ #!/bin/bash # tmp dir -DIR="${TMPDIR-/var/tmp}/fbps-$$" -mkdir -p $DIR || exit 1 +DIR=`mktemp -dt fbgs-XXXXXX` +[ $? -eq 0 ] || exit 1 trap "rm -rf $DIR" EXIT # parse options