CVE-2023-33563 in Time Slots Booking Calendar
Summary
by MITRE • 08/02/2023
In PHP Jabbers Time Slots Booking Calendar 3.3 , lack of verification when changing an email address and/or password (on the Profile Page) allows remote attackers to take over accounts.
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Analysis
by VulDB Data Team • 01/05/2026
The vulnerability identified as CVE-2023-33563 affects the PHP Jabbers Time Slots Booking Calendar version 3.3, presenting a critical security flaw in the user authentication and account management system. This weakness stems from insufficient validation mechanisms during email address and password modification processes within the profile management interface. The flaw allows remote attackers to exploit the system's lack of proper verification procedures to hijack user accounts without requiring legitimate credentials.
The technical implementation of this vulnerability resides in the absence of proper session validation and authentication checks when users attempt to modify their account details. When a user navigates to the profile page and attempts to change their email address or password, the system fails to verify that the request originates from the legitimate account holder. This absence of verification creates an attack vector where malicious actors can manipulate the account modification process to redirect email addresses or reset passwords, effectively gaining unauthorized access to user accounts. The flaw operates at the application layer and represents a classic case of insufficient access control and authentication validation.
The operational impact of this vulnerability extends beyond simple account compromise, as it enables attackers to perform a wide range of malicious activities within the compromised accounts. Once an attacker successfully takes over an account, they can access all associated booking data, modify existing appointments, create new bookings, and potentially disrupt the entire calendar system's functionality. This vulnerability particularly affects businesses and organizations that rely on the calendar system for scheduling critical operations, as unauthorized access could lead to service disruptions, data breaches, and potential financial losses. The remote nature of the attack means that threat actors do not require physical access to the system or knowledge of the victim's current password to exploit this weakness.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and authentication mechanisms within the profile management system. The solution requires the implementation of proper session verification before allowing any account modifications, including the requirement for current password confirmation when changing email addresses or passwords. Additionally, the system should enforce strict validation of email addresses through confirmation mechanisms and implement rate limiting to prevent automated exploitation attempts. Organizations should also consider implementing multi-factor authentication for account modifications and establishing proper audit logging to detect suspicious account activity. This vulnerability aligns with CWE-306, which addresses missing authentication for critical functions, and maps to ATT&CK technique T1078.004 for valid accounts, as it enables unauthorized access through account takeover rather than credential theft. The remediation process should include immediate code review to ensure all user profile modification functions properly validate user identity and implement proper access controls to prevent unauthorized account changes.