Version 3.0.7 of the Securly Chrome Extension has several critical security flaws. These vulnerabilities include insecure data transmission over HTTP for sensitive filtering rules. Weak cryptography is used, as evidenced by hardcoded plaintext AES passphrases and an outdated key derivation method. Improper access control allows unauthenticated access to protected resources and sensitive configuration data. An attacker could exploit these weaknesses to steal filtering information. They might also induce a Denial of Service by manipulating downloaded configuration files. Furthermore, attackers could modify content blocking rules for student users. One vulnerability involves a dynamically registered content script that bypasses security reviews. This script can hide all page content indefinitely if Securly's servers are unreachable. The extension also uses deprecated SHA-1 hashing for critical URL matching. While Securly has not been reached for a patch, administrators can mitigate risk by restricting extension use on untrusted networks and utilizing school-managed VPNs.