CVE-2023-51297 in Hotel Booking System
Summary
by MITRE • 02/19/2025
A lack of rate limiting in the 'Email Settings' feature of PHPJabbers Hotel Booking System v4.0 allows attackers to send an excessive amount of email for a legitimate user, leading to a possible Denial of Service (DoS) via a large amount of generated e-mail messages.
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Analysis
by VulDB Data Team • 03/07/2026
The vulnerability identified as CVE-2023-51297 represents a critical security flaw within the PHPJabbers Hotel Booking System version 4.0 that stems from inadequate rate limiting mechanisms in the email settings functionality. This weakness creates a pathway for malicious actors to exploit the system's email sending capabilities without proper restrictions, potentially overwhelming the server's email infrastructure and disrupting legitimate service operations. The vulnerability specifically targets the email configuration component that handles user notifications and communication within the hotel booking platform, making it particularly dangerous given the system's role in managing reservations and guest communications.
The technical implementation of this vulnerability manifests through the absence of any form of rate limiting or throttling controls when processing email sending requests through the administrative email settings interface. Attackers can leverage this flaw to repeatedly submit email generation requests for legitimate user accounts, causing the system to dispatch excessive email messages without any mechanism to detect or prevent abnormal usage patterns. This lack of validation and control creates a scenario where automated scripts or malicious actors can flood the email infrastructure, consuming bandwidth, processing resources, and potentially triggering spam filters that could impact legitimate email delivery to actual users.
The operational impact of CVE-2023-51297 extends beyond simple service disruption to encompass potential business continuity risks and reputational damage. When an attacker successfully exploits this vulnerability, they can effectively render the hotel booking system's email functionality unusable for legitimate users, as the system becomes overwhelmed with generated messages. The DoS condition can persist until the administrator manually intervenes to reset or modify the email configuration, potentially causing lost reservations, delayed communications with guests, and overall degradation of service quality. This vulnerability particularly affects environments where the booking system handles high volumes of transactions and where email notifications are critical for business operations.
From a cybersecurity perspective, this vulnerability aligns with CWE-770, which describes the allocation of resources without proper limits or management, and represents a clear violation of the principle of least privilege and resource management best practices. The flaw also maps to ATT&CK technique T1499.004, which covers "Toggle System Defense: Email Collection," as attackers can leverage the email system to overwhelm legitimate communication channels. Organizations should implement immediate mitigations including implementing rate limiting controls, establishing email sending quotas, and monitoring email generation patterns for anomalous behavior. Additionally, the system should be updated to version 4.1 or later where the rate limiting functionality has been properly implemented to prevent excessive email generation while maintaining legitimate user communication capabilities.