Weblogic反序列化在各大论坛的讨论一直是轰轰烈烈的,引发本漏洞其实并不能怪java的反序列化机制,本屌丝曾经也写过几行java代码,并且对weblogic的使用也稍微有点基础。
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刚好朋友有个应用使用的是weblogic10.3.6 版本,并且使用WebLogic_EXP.jar 成功执行命令,还好没有被入侵,万幸!!!
测试漏洞存在,应朋友的要求帮忙做个补救,翻遍网上大牛们的技术贴,有两种临时补救的方法,但是尝试过之后对应用有影响,放弃!
今天找到某牛写的贴子,里面提到可以自己禁止JVM 执行系统命令,经过一番研究,写了个servlet 放在系统里面跑了一下,成功防御,直接贴出代码:
import java.io.IOException;
import java.io.PrintWriter;
import java.security.Permission;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySecurityServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public MySecurityServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request,response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>Errot</TITLE></HEAD>");
out.println(" <BODY>");
out.println("Security denied!!!");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
SecurityManager originalSecurityManager = System.getSecurityManager();
if (originalSecurityManager == null) {
// 创建自己的SecurityManager
SecurityManager sm = new SecurityManager() {
private void check(Permission perm) {
// 禁止exec
if (perm instanceof java.io.FilePermission) {
String actions = perm.getActions();
if (actions != null && actions.contains("execute")) {
System.out.println("警告:>>检测到 weblogic 反序列化攻击...");
throw new SecurityException("execute denied!");
}
}
// 禁止设置新的SecurityManager,保护自己
if (perm instanceof java.lang.RuntimePermission) {
String name = perm.getName();
if (name != null && name.contains("setSecurityManager")) {
System.out.println("警告:<<检测到 weblogic 反序列化攻击...");
throw new SecurityException("System.setSecurityManager denied!");
}
}
}
public void checkPermission(Permission perm) {
check(perm);
}
public void checkPermission(Permission perm, Object context) {
check(perm);
}
};
System.setSecurityManager(sm);
}
}
}
web.xml 配置文件中添加如下内容:
<servlet>
<servlet-name>MySecurityServlet</servlet-name>
<servlet-class>MySecurityServlet</servlet-class>
<load-on-startup>0</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>MySecurityServlet</servlet-name>
<url-pattern>/servlet/MySecurityServlet</url-pattern>
</servlet-mapping>
下面是本地测试的结果
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