Two Novel Server-Side Attacks against Log File in Shared Web Hosting Servers

TL;DR

This paper identifies two new server-side attacks exploiting shared log files in shared web hosting environments, revealing private website information and enabling further malicious activities.

Contribution

It introduces two novel attacks on shared hosting log files and proposes countermeasures to enhance security through log file separation.

Findings

Attacks can disclose private website structures

Manipulation of log files enables complex attacks

Countermeasures improve hosting security

Abstract

Shared Web Hosting service enables hosting multitude of websites on a single powerful server. It is a well-known solution as many people share the overall cost of server maintenance and also, website owners do not need to deal with administration issues is not necessary for website owners. In this paper, we illustrate how shared web hosting service works and demonstrate the security weaknesses rise due to the lack of proper isolation between different websites, hosted on the same server. We exhibit two new server-side attacks against the log file whose objectives are revealing information of other hosted websites which are considered to be private and arranging other complex attacks. In the absence of isolated log files among websites, an attacker controlling a website can inspect and manipulate contents of the log file. These attacks enable an attacker to disclose file and directory structure of other websites and launch other sorts of attacks. Finally, we propose several countermeasures to secure shared web hosting servers against the two attacks subsequent to the separation of log files for each website.