A national retail chain headquartered in Minneapolis, Minnesota operates a customer rewards portal supported by...

The correct answer is C. Web Cache Poisoning Attack.

The key indicators are:

The altered content is served to other users.

The origin server still returns the legitimate response.

The issue disappears after cache expiration or replacement.

The crafted request uses headers and parameters that influence cached output.

CEH-aligned web server material explains that Web Cache Poisoning occurs when an attacker sends a crafted request into the cache and stores fake entries, causing users to be redirected or served malicious content . Another CEH-aligned reference explains that a web cache stores copies of responses to speed up future requests, and if an attacker forces malicious or manipulated content into the cache, later visitors can receive that poisoned response .

Option A. DNS Server Hijacking is incorrect because DNS records or DNS server settings are not being modified.

Option B. DNS Rebinding Attack is incorrect because the scenario concerns cached web content, not browser access to private-network resources through DNS rebinding.

Option D. SQL Injection Vulnerability is incorrect because the behavior is tied to delivery-layer caching, not database query manipulation.

Therefore, the best answer is C. Web Cache Poisoning Attack.