GetSimpleCMS Version 3.2.1 Arbitrary File Upload Vulnerability
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# Exploit Title: GetSimpleCMS Version 3.2.1 Arbitrary File Upload Vulnerability
# Download link: http://code.google.com/p/get-simple-cms/
# version: 3.2.1
# Category: webapps
# Tested on: ubuntu 13.4
# Author: Ahmed Elhady Mohamed
# Email: ahmed.elhady.mohamed@gmail.com
# Website: www.itsec4all.com
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Description:
- GetSimpleCMS Version 3.2.1 suffers from arbitrary file upload vulnerability which allows an attacker to upload a HTML page.
- The main reason of this vulnerability is that the application uses a blacklist technique to compare the file aganist mime types and extensions.
- If the mime type or the extension is in the blacklist array , the application won't upload it.
Exploit:
- For exploiting this vulnerability we will create a file with mutiple extensions for example "exploit.html.fr"
- The application will check the mime type and extension of the file which is "fr" aganist the blacklist array mime type and extensions.
- and ofcourse "fr" extension won't be in the blacklist array so the application will upload it successfully.
- The uploaded file will be under the "data/uploads/" folder.
Solution:
- The application should use whitelisting technique which compare the file extensions and mime types aganist
- acceptable mime types and extensions for more information google for "whitelisting vs blacklisting"