A SQL injection vulnerability exists in the PHP RSS Reader 2010 application. An attacker can exploit this vulnerability to gain access to the application's database and extract sensitive information such as usernames and passwords. The vulnerability is due to the application not properly sanitizing user-supplied input before using it in an SQL query. An attacker can exploit this vulnerability by sending a specially crafted HTTP request containing malicious SQL statements to the vulnerable application. This will cause the application to execute the malicious SQL statements and return the results of the query.