The SecOps Group CAP Exam - Topic 9 Question 104 Discussion

CORS (Cross-Origin Resource Sharing) is a mechanism that allows servers to specify which origins can access their resources, enhancing security for cross-origin requests. A common misconfiguration occurs with the Access-Control-Allow-Origin and Access-Control-Allow-Credentials headers. When Access-Control-Allow-Origin is set to * (wildcard, allowing all origins), it permits any domain to make requests. However, if Access-Control-Allow-Credentials is set to true (allowing credentials like cookies or HTTP authentication), this creates a security risk. Browsers will block such requests because sending credentials with a wildcard origin violates CORS security policies, but an attacker could exploit this misconfiguration to trick a victim's browser into making unauthorized requests if other controls are absent.

Option A is correct because the combination of Access-Control-Allow-Origin: * and Access-Control-Allow-Credentials: true is exploitable, as it enables potential credential leakage or unauthorized access. Option B is incorrect because Access-Control-Allow-Credentials: false disables credential sending, reducing exploitability. Option C is incorrect because the value of Access-Control-Allow-Credentials is not irrelevant; it must be false with a wildcard origin to comply with security standards. Option D ('All of the above') is incorrect as only A holds true. This is a key topic in the CAP syllabus under 'CORS Misconfiguration' and 'Client-Side Security.'