CVE-2023-40763 in Taxi Booking Script
Summary
by MITRE • 08/28/2023
User enumeration is found in PHPJabbers Taxi Booking Script v2.0. This issue occurs during password recovery, where a difference in messages could allow an attacker to determine if the user is valid or not, enabling a brute force attack with valid users.
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Analysis
by VulDB Data Team • 01/28/2026
The vulnerability identified as CVE-2023-40763 represents a critical user enumeration flaw within the PHPJabbers Taxi Booking Script version 2.0 that significantly undermines the application's security posture. This weakness manifests during the password recovery process where the system provides differential response messages to users, creating a timing or content-based information leak that can be exploited by malicious actors. The vulnerability stems from the application's failure to implement consistent error handling mechanisms during authentication-related operations, allowing attackers to distinguish between valid and invalid user accounts through subtle variations in system responses.
From a technical perspective, this user enumeration vulnerability operates under the Common Weakness Enumeration framework as CWE-204, which specifically addresses information exposure through response differences. The flaw occurs when the password recovery mechanism returns different error messages or response times for legitimate versus non-existent user accounts, enabling an attacker to perform a systematic enumeration attack. When an attacker submits a username during password recovery, the system's response varies depending on whether the account exists, creating a predictable pattern that can be exploited through automated tools to identify valid users within the system.
The operational impact of this vulnerability extends beyond simple information disclosure, as it directly enables brute force attacks and credential stuffing campaigns that can lead to unauthorized account access and potential system compromise. Attackers can systematically test usernames against the password recovery functionality to build a comprehensive list of valid accounts, which then becomes the foundation for more sophisticated attacks including password guessing, account takeover attempts, and social engineering exploitation. This vulnerability particularly affects organizations using the PHPJabbers Taxi Booking Script as it provides attackers with a low-effort method to identify valid user credentials within the system, significantly reducing the attack surface for subsequent exploitation phases.
The implications of this vulnerability align with several ATT&CK framework techniques including T1078 Valid Accounts for maintaining persistence and T1110 Brute Force for credential access. Organizations utilizing this software face heightened risk of unauthorized access and data breaches, particularly if the system contains sensitive user information or transactional data related to taxi services. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous in environments where user enumeration is not properly mitigated through consistent error handling or rate limiting mechanisms.
Effective mitigation strategies for CVE-2023-40763 should focus on implementing uniform error responses regardless of account validity during password recovery operations. The system should return identical messages for both valid and invalid usernames, ensuring that no information is leaked about account existence through response variations. Additionally, implementing robust rate limiting and account lockout mechanisms can prevent automated enumeration attempts, while logging and monitoring systems should be configured to detect suspicious patterns of username enumeration attempts. Organizations should also consider implementing multi-factor authentication as an additional security layer to protect against credential compromise even if user enumeration occurs. The fix should be implemented as a code-level modification to ensure all authentication-related functions return consistent responses, thereby eliminating the information leak that enables this particular class of attack.