Use of Web Browser Cache Containing Sensitive Information
This vulnerability occurs when a web application fails to implement secure caching directives, allowing sensitive user data or pages to be stored in the browser's cache where unauthorized parties could retrieve them.
When a web server doesn't send the correct HTTP cache-control headers (like `no-store`, `private`, or appropriate `max-age`), browsers will save copies of pages, form data, or API responses by default. This means sensitive information such as login credentials, personal details, or session tokens could be written to the user's disk, remaining accessible after logout or even to other users on a shared computer. To prevent this, developers must explicitly define a restrictive caching policy for all sensitive content. This involves setting HTTP response headers to instruct the browser not to cache certain pages or to cache them only privately. It's a critical security step that is often overlooked during development but is essential for protecting user privacy and data confidentiality.
Impact: Read Application Data
Browsers often store information in a client-side cache, which can leave behind sensitive information for other users to find and exploit, such as passwords or credit card numbers. The locations at most risk include public terminals, such as those in libraries and Internet cafes.
- OWASP Top Ten 2004
- OWASP Top Ten 2004