Week 12 - web security 2

XSS can be prevented by

• input validation and output encoding

• Same Origin Policy

• Cross Origin Policy

• Content Security Policy

• Data authentication of scripts

Where can SQL injection be performed

• Web forms

• Browser URL

• PDF documents

• Note pad

The image is an example of __________ against SQL injection

• Filtering (Black listing)

• Replacing dangerous characters with encoding

• Parameterized queries

• Reassigning variables

Which is true about XSS

• The developers of the application are the ones at risk

• Its main target is the application itself

• It is a form of code injection

• XSS attacks run a script in the browser that was not written by the web application owner

Which html tag(s) is used by the attacker to perform XSS

• <div>

• <script>

• <exe>

• <npm>

Which DOM code is executes the script tag?

• document.querySelectorAll()

• document.Inject()

• document.queryAll()

• document.querySelector()

Non-persistent XSS is known as

• Stored XSS

• Reflected XSS

• DOM-Based XSS

• Request-Based XSS

What makes DOM-based XSS different from XSS/Reflected XSS?

• It requires server sided flaws

• It requires client sided flaws

• It modifies the DOM environment

• It executes only on the victims browser

What are the limitations with Filtering input/outputs for XSS?

• Only works well with clear rules characterzing good/bad inputs

• Not centrally forcable due to scattered code

• Need constant updates on filters

• Have to deal with unspecified browser behaviour

What are some ways to defend against XSS attacks through Improved Access Control

• Server can sign scripts (PKI), client uses public key to verify

• Apply MAC to scripts, only server needs secret key

• Only allow authorized scripts to be loaded for a given page (Content Security Policy)

• Create ACLs and Capabilities on the DOM rendered on the client side.