Vikunja is an open-source self-hosted task management platform. Starting in version 0.8 and prior to version 2.2.0, unauthenticated users are able to bypass the application's built-in rate-limits by spoofing the X-Forwarded-For or X-Real-IP headers due to the rate-limit relying on the value of (echo.Context).RealIP. Unauthenticated users can abuse endpoints available to them for different potential impacts. The immediate concern would be brute-forcing usernames or specific accounts' passwords. This bypass allows unlimited requests against unauthenticated endpoints. Version 2.2.0 patches the issue.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:L5.3/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LOther