Traffic Sniffing

Traffic Sniffing is a reconnaissance sub-technique that involves intercepting and analyzing network communications to discover API specifications, endpoints, and parameters without direct access to API documentation. During the Application API Specification Harvesting phase, attackers employ network monitoring tools like Wireshark, Burp Suite, or Charles Proxy to passively capture HTTP/HTTPS traffic between client applications and API servers. By analyzing these intercepted requests and responses, attackers can identify API endpoints, understand authentication mechanisms, extract data structures, and map available API operations. This technique is particularly effective against mobile applications, single-page web applications (SPAs), and IoT devices that communicate with backend services, as these often reveal comprehensive API interactions during normal operation. Successful traffic sniffing can provide attackers with sufficient information to construct unauthorized API requests, circumvent security controls, or identify potential vulnerabilities in the API implementation, making it a critical precursor to more advanced API-focused attacks.

Long-Term Reconnaissance Techniques

Long-term reconnaissance techniques involve an attacker continuously crawling previously identified and new endpoints. By examining HTTP response variations over time, attackers can identify recent API changes. If these changes process sensitive functions or data, they can serve as prime targets because they may not have been fully vetted by the organization.