A penetration tester uncovered a flaw in an online banking web application that allows arbitrary requests to other internal network assets through a server-side request forgery. Which of the following would BEST reduce the risk of attack?
A penetration tester uncovered a flaw in an online banking web application that allows arbitrary requests to other internal network assets through a server-side request forgery. Which of the following would BEST reduce the risk of attack?
Server-side request forgery (SSRF) occurs when an attacker can manipulate a web application to send unauthorized requests on behalf of the server to internal network resources. The most effective way to mitigate SSRF attacks is to ensure that all input is properly sanitized and validated within the web application. By sanitizing and validating input, you can prevent malicious requests from being crafted and executed. This measure directly addresses the core of the SSRF vulnerability by controlling and verifying the data that the web application processes, thereby reducing the risk of unauthorized access to internal network assets.
Server-side request forgery occurs when an attacker can manipulate a web application to send a request on behalf of the application to an internal network asset. By sanitizing and validating all input within the web application, the application can prevent an attacker from injecting malicious code or requests that could result in unauthorized access to internal resources.
Implementing multifactor authentication (A), configuring a secret management solution (B), and ensuring a patch management system is in place (C) are important security measures but they do not directly address the server-side request forgery vulnerability in the web application. Enabling enhanced logging (E) can help in detecting an attack, but it is not a solution to prevent the attack from happening in the first place. Therefore, D is the BEST option to reduce the risk of attack.
Prevention and Mitigation Input Validation and Sanitization: Ensure that all inputs that could be used to form URLs are properly validated and sanitized. Only allow requests to whitelisted domains or IP addresses if possible. Network Segmentation: Isolate critical internal services and ensure they are not accessible from the public internet or other less trusted segments of the network. Access Control: Implement strict access controls and firewalls to limit what internal resources the server can reach. Use Metadata Protection: In cloud environments, configure metadata endpoints to be protected and inaccessible from untrusted sources. Monitoring and Logging: Monitor and log outgoing requests from your servers to detect any unusual or unauthorized activity.
The best way to mitigate the risk of server-side request forgery (SSRF) attacks is to properly sanitize and validate all input within the web application. By doing so, the application can prevent attackers from crafting malicious requests that target internal network assets. Implementing input validation and sanitization helps ensure that only permitted and safe requests are processed, thereby reducing the risk of SSRF attacks. While the other options may improve overall security, they do not directly address the specific vulnerability of SSRF
D. Sanitize and validate all input within the web application to prevent internal resources from being accessed. The other options, while representing good security practices in general, do not specifically address the SSRF vulnerability.