WordPress (CMS) mTheme-Unus css.php

There is an arbitrary file download vulnerability in the WordPress theme mTheme-unus. An attacker can request the download of a file residing anywhere on the server, such as /etc/passwd. The resulting attack could lead to the compromise of the server by exposing usernames and passwords. 

Exploitation

Stages

1. A remote unauthenticated attacker sends a HTTP request to css.php, requesting the download of a file present in the server, such as /etc/passwd.
2. The server responds with the contents of the file.

Prerequisites

The vulnerable plugin must be installed on the server.

Vulnerability Description

There is an arbitrary file download vulnerability in the WordPress theme mTheme-unus. The vulnerability resides within the css.php which does not carry out checks on the level of authentication of the user requesting the file. It also does not sanitize the type of file being downloaded. An attacker can request the download of a file residing anywhere on the server, such as /etc/passwd. The resulting attack could lead to the compromise of the server by exposing usernames and passwords.

Alert Logic Coverage

Alert Logic® has evaluated its customer base for exposure to the exploit and has developed signatures for mitigating the threat depending on the security service in place.

The Network-Based Intrusion Detection System (IDS) has been updated with the new signatures for this exploit when detected via Alert Logic Threat Manager™. If this signature is detected, an incident is generated in the Alert Logic console.

Recommendations for Mitigation

Upgrade to a non-vulnerable version of the plugin to mitigate the vulnerability.