{"id":"GHSA-j5mc-p8qg-39j7","aliases":[],"url":"https://o3.security/vulnerability/GHSA-j5mc-p8qg-39j7","summary":"Kimai Favorite Timesheet Add and Remove Endpoints Allows Cross-User Bookmark Manipulation","details":"### Summary\n\nKimai 2.56.0 contains an authenticated improper authorization / IDOR vulnerability in the favorite timesheet add and remove endpoints. A low-privileged user who knows another user's `timesheet.id` can add that record to, or remove it from, the victim's `favorite/recent` bookmark list. This allows cross-user manipulation of per-user favorite state without administrative privileges.\n\n### Details\n\nThe issue affects the following routes:\n\n- `GET /en/favorite/timesheet/add/{id}`\n- `GET /en/favorite/timesheet/remove/{id}`\n\nBoth endpoints accept a user-controlled timesheet identifier and only require the caller to hold the generic `start_own_timesheet` permission. They do not verify that the referenced `Timesheet` object belongs to the currently authenticated user.\n\n- In `src/Controller/FavoriteController.php`, the controller methods accept a `Timesheet` object directly and forward it to the favorite service. \n- The root cause becomes more obvious in `src/Timesheet/FavoriteRecordService.php`. The bookmark owner is derived from `$timesheet->getUser()` instead of the current session user.\n- Because of this design, any authenticated user who can reference another user's timesheet ID can modify the victim's `favorite/recent` bookmark data.\n\n*A PoC was provided, but removed for security reasons.*\n\n### Impact\n\nThis vulnerability allows any authenticated low-privileged user to manipulate another user's favorite bookmark state across accounts. An attacker can inject arbitrary victim-owned timesheet entries into the victim's quick-entry workflow, remove existing favorites, and repeatedly disturb the victim's normal timesheet usage without needing administrative privileges.\n\nThe issue does not directly disclose sensitive data, but it is a real cross-user business-state tampering vulnerability with clear integrity impact. Because the add and remove endpoints can be combined, an attacker can reliably insert, remove, and reorder entries in another user's `favorite/recent` list.","published":"2026-07-02T20:44:05Z","modified":"2026-07-02T20:45:16.396200372Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"kimai/kimai","fixedVersion":"2.57.0"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/kimai/kimai/security/advisories/GHSA-j5mc-p8qg-39j7"},{"type":"PACKAGE","url":"https://github.com/kimai/kimai"},{"type":"WEB","url":"https://www.kimai.org/en/security/ghsa-j5mc-p8qg-39j7"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-02T20:45:16.396200372Z"}}