Strict transport security not enforced
Summary: PortSwigger Research describes a vulnerability where an application fails to prevent users from connecting over unencrypted connections, allowing an attacker who can modify a legitimate user's traffic to rewrite HTTPS links as HTTP so the browser never attempts an encrypted connection, a process automated by the sslstrip tool. The fix is to enable HTTP Strict Transport Security by adding a 'Strict-Transport-Security' response header with a 'max-age' value, optionally with the 'includeSubDomains' and 'preload' flags, though HSTS is trust-on-first-use so a user who has never visited the site remains vulnerable to SSL stripping.
What you should know: The exposure is widest on public Wi-Fi and shared corporate or home networks, where switched networks are not sufficient to stop the attack, and an attacker positioned in the user's ISP or the application's hosting infrastructure could also carry it out.
Read the original at PortSwigger Research ↗
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