Understanding HTTPS and Mixed Content on the Web

When a 💻 user visits a page 🌐 served over HTTP , their connection ↔️ is open for eavesdropping and man-in-the-middle (MITM) attacks. When a user visits a page served over HTTPS, their connection with the web server is authenticated and encrypted with SSL and hence safeguarded from eavesdroppers and MITM attacks 🥷.

However, if an HTTPS page includes HTTP content, the HTTP portion can be read or modified by attackers, even though the main page is served over HTTPS. When an HTTPS page has HTTP content, we call that content “mixed”. The webpage that the user is visiting is only partially encrypted, since some of the content is retrieved ⏪ unencrypted over HTTP. The Mixed Content Blocker blocks certain HTTP requests on HTTPS pages.

In addition to defending against mixed content vulnerabilities, browsers play a crucial role in safeguarding users from unsafe addresses. When a browser identifies a connection attempt to a non-secure HTTP address, it takes proactive measures to protect the user. Modern browsers are equipped with features that automatically redirect users from HTTP to HTTPS, ensuring that sensitive information is transmitted securely. By actively addressing potential security risks, browsers contribute significantly to creating a safer online environment for users, protecting them from the pitfalls associated with non-secure connections.

In essence, while HTTPS ensures a secure connection, the presence of mixed content, where HTTP elements coexist with HTTPS, introduces vulnerabilities. Browsers, equipped with features like the Mixed Content Blocker, act as gatekeepers to mitigate these risks. As cybersecurity practitioners, it is pivotal to emphasize the adoption of HTTPS and advocate for secure web practices to uphold a resilient defense against evolving online threats.