Frequently Asked Questions
What is a CSP and why is it important?
A Content Security Policy (CSP) is a web security feature that helps prevent internet-based attacks, especially XSS, by controlling the resources a web page can load. It is important because it adds an core layer of security by specifying which content sources are trusted.
What are the risks of using unsafe-inline?
Using unsafe-inline in a Content Security Policy (CSP) allows the execution of inline scripts, which attackers can exploit to inject and run malicious code. unsafe-inline effectively bypasses the protections provided by a CSP against Cross-Site Scripting (XSS) attacks, significantly increasing the risk of a successful XSS exploit.
A successful XSS attack can lead to session hijacking by compromising session cookies or tokens, potentially allowing attackers to impersonate legitimate users. This can result in account takeovers or other session-related vulnerabilities, such as replay attacks.
How can I safely implement inline scripts?
If you must use inline scripts, consider using a hash and nonce-based CSP. I find that often I am using both together, this allows specific inline scripts to execute only if the hash and the nonce validate, thus maintaining tighter control over script execution.
What tools can help with CSP evaluation?
Tools like Google’s CSP Evaluator and various browser extensions can help analyze your CSP, identify vulnerabilities, and monitor your programming team’s fixes on CSP violations in real time.
How often should I review my CSP?
Regular reviews of your CSP are essential, especially whenever you make changes to your application or add new external resources. Ideally this is an automated daily check, then received in a report or API endpoint. Ensure that your security measures remain effective against potential threats.
