Rejetto HFS 3.0.0 through 3.2.0 returns observably different responses from its login endpoint depending on whether the submitted username exists. A remote unauthenticated attacker can use this to confirm valid account names, including the default admin account, facilitating password-guessing and session-forgery attacks.

Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's state, recover the signing key, and forge a valid administrator session cookie, leading to full administrative access and remote code execution via the servercode configuration feature.

Rejetto HFS 3.0.0 through 3.2.0 allows path traversal through the lang query parameter, permitting a remote unauthenticated attacker to read certain JSON files outside the shared folders. Exploitation is constrained to files matching a narrow naming and format pattern, limiting practical impact.

Rejetto HFS 3.0.0 through 3.2.0 does not escape file names in its fallback "basic" web listing, and this listing can be forced by any browser via the ?get=basic parameter. A user with upload permission - or an anonymous user on servers with an open upload folder - can store a file whose name contains script that executes in the browser of anyone viewing the listing.

Rejetto HFS 3.0.0 through 3.2.0 accepts state-changing API requests via the GET method and exempts GET requests from its anti-CSRF header check. A remote attacker can perform administrative actions including account creation and configuration changes leading to code execution - by causing a logged-in administrator's browser to navigate to a crafted URL, or without any credentials against default installations when the attack originates from the server's own machine.

Rejetto HFS 3.0.0 through 3.2.0 renders log entries in the administration panel as HTML without sanitization. A remote unauthenticated attacker can submit a failed login with a crafted username that is written to the error log and executes JavaScript in an administrator's browser when the logs are viewed, allowing the attacker to create accounts or execute code on the server with the administrator's privileges.