Information Systems Security (Paperback)

Paperback. 2.1 Web Application Vulnerabilities Many web application vulnerabilities havebeenwell documented andthemi- gation methods havealso beenintroduced [1]. The most common cause ofthose vulnerabilities isthe insu?cient input validation. Any data originated from o- side of the program code, forexample input data provided by user through a web form, shouldalwaysbeconsidered malicious andmustbesanitized before use.SQLInjection, Remote code execution orCross-site Scriptingarethe very common vulnerabilities ofthattype [3]. Below isabrief introduction toSQL- jection vulnerability though the security testingmethodpresented in thispaper is not limited toit. SQLinjectionvulnerabilityallowsanattackertoillegallymanipulatedatabase byinjectingmalicious SQL codes into the values of input parameters of http requests sentto the victim web site. 1: Fig.1. An example of a program written in PHP which contains SQL Injection v- nerability Figure 1 showsaprogram that uses the database query function mysql query togetuserinformationcorrespondingtothe userspeci?edby the GETinput- rameterusername andthen printtheresultto the clientbrowser.Anormalhttp request with the input parameter username looks like "/ index.php?username=bob". The dynamically created database query at line2 is "SELECT * FROM users WHERE username='bob' AND usertype='user'". Thisprogram is vulnerabletoSQLInjection attacks because mysql query uses the input value of username without sanitizingmalicious codes. A malicious code can be a stringthatcontains SQL symbols ork- words.Ifan attacker sendarequest with SQL code ('alice'-') - jected "php?username=alice'-", the query becomes "SELECT* FROM users WHERE username='alice'--' AND usertype='user'". Constitutes the refereed proceedings of the 6th International Conference on Information Systems Security, ICISS 2010, held in Gandhinagar, India, in December 2010. Shipping may be from multiple locations in the US or from the UK, depending on stock availability.…