Putting your Web or mail server on the same server as other sites to save money may have hidden costs.Shared hosting can be a cost-efficient solution for many Web sites, but you may end up paying a different sort of price. As always when sharing with strangers, theres a risk of the unknown. A well-designed and -managed operating system along with other system software may be able to protect applications and users from one another, but things do go wrong at times. Consider what happens when an attacker goes after one of the other sites on your shared server. Vulnerabilities such as the MySQL Password Handler Buffer Overflow Vulnerability or the PHP wordwrap() Heap Corruption Vulnerability may occur. If the attacker gains control of the server or the database, youre all just as vulnerable.
And the attacker may not even be an outsiderit could be another customer.