HTTP Blocking
Intercepting and blocking unencrypted HTTP requests based on content.
Definition
HTTP blocking involves inspecting unencrypted web traffic and blocking requests based on URLs, headers, or content. Since HTTP transmits data in plaintext, network operators can see exactly what pages users request and selectively block access.
This technique is becoming less effective as HTTPS adoption increases, but remains relevant for legacy systems and in contexts where TLS is stripped or blocked entirely.
How We Detect This
We make HTTP requests to test URLs and compare responses against expected content. Blocking is indicated by connection resets, redirects to block pages, injected content, or timeouts. We distinguish HTTP blocking from server-side issues by validating responses from control vantage points.
Examples
- •HTTP request returns government block page
- •Connection reset after HTTP GET request
- •Injected JavaScript redirecting to warning