WordPress – File Upload Authorisation Bypass

Details of BNVL-2018-0040

What does the BNVL label mean?

BitNinja Server Security’s BNVL identifiers are intended for use to identify publicly known information security vulnerabilities in publicly released software packages. This project was designed to collect and analyze attack information from the BitNinja network after cluster analysis by the AI-powered Attack Vector Miner. More than 100 vulnerability types have been discovered with this project so far, so we decided to publish this platform to help to keep Linux server owners up-to-date.

Important! All listed BNVL vulnerabilities are protected by BitNinja PRO, so please check your configurations if your infrastructure is affected by any of them.

Syntax for BNVL labels:

BNVL prefix + Year + Arbitrary Digits

Name :
WordPress – File Upload Authorisation Bypass
Related Links: http://seclists.org/fulldisclosure/2012/Jun/327 



Security-Assessment.com has discovered that the plugin upload function
within the WordPress administrative interface is vulnerable to an
un-validated file upload attack. Whilst the media upload functionality
successfully validates the uploaded file and rejects those not
matching the correct extension, the plugin upload functionality does
not. This allows an authenticated WordPress administrative user to
upload arbitrary files, including a malicious PHP script, into the
WordPress web-root.
If a WordPress plugin has previously been installed, WordPress will
use saved SFTP credentials as part of the upload process. If the
credentials have changed or a plugin has not previously been
installed, the application prompts the user for credentials.
Regardless of installation status and prior to the user being prompted
for SFTP credentials, the file is uploaded into the
“/wp-content/uploads/” directory.

Pattern: /wp-admin/plugin-install.php?tab=upload