01:198:419 Lecture Notes - Lecture 8: Cross-Site Scripting, Http Cookie, Web Server
7 May 2016
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Document Summary
Web applications: online banking, shopping, gov"t etc, website takes user input, interacts with back-end databases/third parties, outputs results via generation of a html page, often written from scratch in a mixture of languages. Security often isn"t the main concern: poorly written scripts with inadequate input validation often are easily exposed, sensitive data is often stored in files not well hidden from the global internet users. Since userfound. eof is always false; authentication is always correct: another example, to authenticate logins, server runs sql command against the user database. Select * where user="name" and pwd="passwd: malicious attacker then enters this: " exec cmdshell "net user badguy badpwd" / add : then the server creates an account for the attacker on the database, in order to fix, always escape user supplied arguments, convert " into \" Http protocol: http used to request and return data, get, post, head etc.
