CEH Web Application and Injection Attacks Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  DOM-based XSS

  Why this is correct

  DOM-based Cross-Site Scripting (XSS) arises when a web application's client-side script processes user-controllable data from the Document Object Model (DOM) unsafely, without sending it back to the server. The vulnerability occurs entirely within the browser, where malicious input directly modifies the DOM environment via JavaScript, leading to script execution. This typically involves a "source" like document.URL and a "sink" like eval() or innerHTML, making it a client-side vulnerability that doesn't necessarily involve server-side reflection.

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  Blind XSS

  Why it's wrong here

  Blind XSS is a specialized form of stored Cross-Site Scripting where the malicious payload is saved on the server but is not immediately reflected back to the attacker's browser. Instead, it is triggered much later by a different user or system, often within an internal application like an administrative panel, customer support interface, or logging system. The attacker "blinds" the payload, waiting for an unsuspecting victim to interact with the stored data, making detection more challenging.

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  Self-XSS

  Why it's wrong here

  Self-XSS is a social engineering attack rather than a direct web application vulnerability, as it requires the victim to manually paste and execute malicious JavaScript code into their own browser's developer console. The application itself does not process or reflect the input unsafely; the user is tricked into executing the script locally. Therefore, it does not represent a flaw that an attacker can exploit against other users without their direct, misguided intervention, making it distinct from exploitable XSS types.

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  Stored (persistent) XSS

  Why it's wrong here

  Stored, or persistent, Cross-Site Scripting occurs when a malicious script is permanently saved on the target server, typically within a database, and subsequently delivered to other users without proper sanitization. Once stored, the payload is served to every user who accesses the affected web page, making it a highly impactful vulnerability. Examples include comments sections, user profiles, or forum posts where input is saved and later retrieved, affecting multiple victims over time.

• ✓

  Reflected XSS

  Why this is correct

  Reflected Cross-Site Scripting (XSS) occurs when a malicious script injected into an HTTP request is immediately and unsafely echoed back in the web server's response. This non-persistent attack requires the victim to click a specially crafted URL containing the payload, which is then executed by their browser. The server processes the input but fails to sanitize it before reflecting it back, making it a client-side vulnerability initiated by a server-side flaw that requires user interaction for exploitation.

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