Improving Web Application Security: Threats and - CGISecurity

Chapter 2: Threats and Countermeasures 15Survey andAssessExploit andPenetrateEscalate PrivilegesMaintain AccessDeny ServiceFigure 2.1Basic steps for attacking methodologySurvey and AssessSurveying and assessing the potential target are done in tandem. The first step anattacker usually takes is to survey the potential target to identify and assess itscharacteristics. These characteristics may include its supported services and protocolstogether with potential vulnerabilities and entry points. The attacker uses theinformation gathered in the survey and assess phase to plan an initial attack.For example, an attacker can detect a cross-site scripting (XSS) vulnerability bytesting to see if any controls in a Web page echo back output.Exploit and PenetrateHaving surveyed a potential target, the next step is to exploit and penetrate. If thenetwork and host are fully secured, your application (the front gate) becomes the nextchannel for attack.For an attacker, the easiest way into an application is through the same entrance thatlegitimate users use — for example, through the application’s logon page or a pagethat does not require authentication.Escalate PrivilegesAfter attackers manage to compromise an application or network, perhaps byinjecting code into an application or creating an authenticated session with theMicrosoft ® Windows ® 2000 operating system, they immediately attempt to escalateprivileges. Specifically, they look for administration privileges provided by accountsthat are members of the Administrators group. They also seek out the high level ofprivileges offered by the local system account.