Cross-Site Scripting (XSS) Overview Quiz Answers 1. What is the primary purpose of implementing a Content Security Policy (CSP)? A. To conduct penetration testing and identify vulnerabilities. B. To encrypt cookies and prevent unauthorized access. C. To validate user input format before accepting it. D. To control which sources of scripts and stylesheets can be loaded by the browser. Answer: To control which sources of scripts and stylesheets can be loaded by the browser. (D) A Content Security Policy is designed to mitigate XSS attacks by controlling script sources. 2. Which of the following is NOT an input validation technique to prevent XSS attacks? A. Allowing all characters without restriction. B. Encoding output data before display. C. Escaping special characters in user input. D. Thoroughly validating expected input formats. Answer: Allowing all characters without restriction. (A) Allowing all characters without restriction does not validate user input and increases vulnerability to XSS. 3. How do HttpOnly cookies help mitigate the risks of XSS attacks? A. They enable cookies to be set without user consent. B. They allow scripts to run without restrictions. C. They provide encryption for session data. D. They prevent client-side scripts from accessing the cookies. Answer: They prevent client-side scripts from accessing the cookies. (D) HttpOnly cookies are configured to prevent access by client-side scripts, enhancing session data security. 4. What is a significant benefit of conducting regular security assessments? A. They educate users about online threats. B. They can identify and address potential XSS vulnerabilities. C. They ensure all web applications remain unmodified. D. They create stronger password policies. Answer: They can identify and address potential XSS vulnerabilities. (B) Regular security assessments, including penetration testing, are essential for identifying XSS vulnerabilities. 5. Which practice is recommended to reduce the impact of exploitation in applications? A. Networking all applications for easier access. B. Employing least privilege access for application components. C. Using custom scripts for essential functionalities. D. Ensuring users have admin privileges. Answer: Employing least privilege access for application components. (B) Employing least privilege minimizes the potential damage from exploitation by limiting permissions. 6. What is a Cross-Site Scripting (XSS) attack primarily exploiting? A. Weaknesses in encryption protocols B. Outdated web application frameworks C. User permissions and access levels D. Trust in user-supplied data Answer: Trust in user-supplied data (D) XSS attacks exploit the trust that a web application places in user-supplied data. 7. Which type of XSS attack allows malicious scripts to be executed every time a user accesses stored content? A. DOM-based XSS B. Session-based XSS C. Reflected XSS D. Stored XSS Answer: Stored XSS (D) Stored XSS involves injecting malicious script into a persistent storage, allowing execution when accessed. 8. What is a common method to prevent XSS attacks? A. Validating and sanitizing user input B. Implementing two-factor authentication C. Encrypting all data transmissions D. Increasing server capacity Answer: Validating and sanitizing user input (A) Prevention methods focus on validating and sanitizing user input to prevent malicious script execution. 9. Which attack vector can potentially carry malicious scripts through user input? A. HTTP headers B. Database queries C. Encryption keys D. Session tokens Answer: HTTP headers (A) HTTP headers containing user input data can also carry malicious scripts. 10. What is a potential impact of an XSS attack? A. User interface glitches B. Data breaches C. Increased page load times D. Ransomware attacks Answer: Data breaches (B) XSS attacks can lead to data breaches by stealing sensitive information. 11. How does a reflected XSS attack typically occur? A. Using encrypted cookies B. Through compromised user accounts C. Through maliciously crafted URLs D. By altering browser settings Answer: Through maliciously crafted URLs (C) Reflected XSS involves attackers injecting malicious script into a URL which is then reflected back in the response. 12. In which type of XSS attack is client-side JavaScript involved in executing the malicious script? A. Stored XSS B. Malware-based XSS C. DOM-based XSS D. Reflected XSS Answer: DOM-based XSS (C) DOM-based XSS involves manipulating the Document Object Model (DOM) to execute the malicious script. 13. What might attackers achieve through session hijacking in an XSS attack? A. Selling user data on the dark web B. Increasing website traffic C. Enhancing the site's ranking on search engines D. Impersonating the user on the application Answer: Impersonating the user on the application (D) Session hijacking allows attackers to gain access to a user's session and impersonate them on the application.