Vikunja Task Management Authorization Issues

Vikunja task management application contains an authentication bypass vulnerability in its password reset logic that allows disabled user accounts to be reactivated without authorization. The ResetPassword() function unconditionally sets user status to 'Active' after password reset completion, enabling disabled users to regain full access by requesting a password reset token and completing the reset process. A working proof-of-concept Python script is publicly available demonstrating automated exploitation of this vulnerability.

A permission-check bypass vulnerability exists in Vikunja versions 0.20.2 through 2.1.x where the DELETE /api/v1/projects/:project/background endpoint incorrectly validates CanRead permissions instead of CanUpdate permissions, allowing read-only project members to permanently delete a project's background image. This affects the go-vikunja:vikunja product family, and the vulnerability has been patched in version 2.2.0 as documented in the GitHub security advisory GHSA-564f-wx8x-878h.

An authenticated user in Vikunja can read any task comment by its ID without proper authorization checks, regardless of whether they have access to the task that comment belongs to. The vulnerability exists in the `GET /api/v1/tasks/{taskID}/comments/{commentID}` endpoint, which validates access against the attacker-controlled task ID in the URL but then loads the comment by ID alone, bypassing task ownership verification. Any authenticated attacker with read access to at least one task can enumerate and retrieve comments from arbitrary tasks and private projects, leading to unauthorized information disclosure.