Finding SQL Injection Bugs

In the most obvious cases, a SQL injection flaw may be discovered and conclusively verified by supplying a single item of unexpected input to the application. In other cases, bugs may be extremely subtle and may be difficult to distinguish from other categories of vulnerability or from benign anomalies that do not present any security … Read more

Attacking Access Controls

Before starting to probe the application to detect any actual access control vulnerabilities, you should take a moment to review the results of your application mapping exercises, to understand what the application’s actual requirements are in terms of access control, and therefore where it will probably be most fruitful to focus your attention. The easiest … Read more

Vulnerable Mapping of Tokens to Sessions

Various common vulnerabilities in session management mechanisms arise because of weaknesses in the way the application maps the creation and processing of session tokens to individual users’ sessions themselves. The simplest weakness is to allow multiple valid tokens to be concurrently assigned to the same user account. In virtually every application, there is no legitimate … Read more

Disclosure of Tokens in Logs

Aside from the clear-text transmission of session tokens in network communications, the most common place where tokens are simply disclosed to unauthorized view is in system logs of various kinds. Although it is a rarer occurrence, the consequences of this kind of disclosure are usually more serious because those logs may be viewed by a … Read more

Weaknesses in Session Token Handling

No matter how effective an application is at ensuring that the session tokens it generates do not contain any meaningful information and are not susceptible to analysis or prediction, its session mechanism will be wide open to attack if those tokens are not handled carefully after generation. For example, if tokens are disclosed to an … Read more