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.