Vulnerability Database

361,925

Total vulnerabilities in the database

Kimai Favorite Timesheet Add and Remove Endpoints Allows Cross-User Bookmark Manipulation — kimai / kimai

Authorization Bypass Through User-Controlled Key

Summary

Kimai 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.

Details

The issue affects the following routes:

  • GET /en/favorite/timesheet/add/{id}
  • GET /en/favorite/timesheet/remove/{id}

Both 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.

  • In src/Controller/FavoriteController.php, the controller methods accept a Timesheet object directly and forward it to the favorite service.
  • 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.
  • Because of this design, any authenticated user who can reference another user's timesheet ID can modify the victim's favorite/recent bookmark data.

A PoC was provided, but removed for security reasons.

Impact

This 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.

The 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.

No technical information available.

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.