CVE-2023-40766 in Ticket Support Script
Summary
by MITRE • 08/28/2023
User enumeration is found in in PHPJabbers Ticket Support Script v3.2. 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-2023-40766 represents a critical user enumeration flaw within the PHPJabbers Ticket Support Script version 3.2 that fundamentally undermines the system's authentication security posture. This weakness manifests during the password recovery process where the application provides differential response messages to users, creating a side-channel information leak that directly enables attackers to distinguish between valid and invalid user accounts. The vulnerability stems from insufficient input validation and response handling mechanisms that fail to maintain consistent error messaging regardless of account status, thereby exposing the underlying user directory to systematic enumeration attacks.
From a technical perspective this issue aligns with CWE-200, which categorizes information exposure vulnerabilities where the application inadvertently reveals sensitive information through its responses. The flaw operates as a classic timing and response-based enumeration attack vector where attackers can submit multiple password recovery requests and observe variations in response times or message content to infer valid user accounts. The vulnerability specifically targets the password recovery functionality, which is a common attack surface in web applications due to its inherent trust relationship with users and the sensitive nature of account recovery mechanisms. This weakness creates a direct pathway for credential stuffing and brute force attacks as attackers can systematically identify valid user accounts before attempting to exploit them through other attack vectors.
The operational impact of this vulnerability extends beyond simple account compromise, creating a foundation for more sophisticated attacks within the broader threat landscape. The ability to enumerate valid users enables attackers to focus their efforts on specific targets rather than conducting broad, inefficient brute force attempts. This vulnerability directly maps to techniques described in the MITRE ATT&CK framework under T1078, which covers legitimate credentials and T1110, which covers credential access through brute force and password spraying. The compromised system becomes vulnerable to further attacks including privilege escalation, lateral movement, and data exfiltration once valid user accounts are identified. Organizations utilizing this ticket support script face increased risk of unauthorized access to sensitive support tickets, user data, and potentially broader system resources depending on the application's architecture and access controls.
Mitigation strategies for CVE-2023-40766 must address both the immediate response handling issue and broader authentication security practices. The primary fix involves implementing consistent error messaging during password recovery operations, ensuring that all user accounts receive identical response messages regardless of their validity status. This approach prevents attackers from distinguishing between valid and invalid accounts through response analysis. Additionally, organizations should implement account lockout mechanisms, rate limiting for password recovery requests, and consider implementing multi-factor authentication to add additional security layers. The solution should also incorporate proper logging and monitoring to detect unusual patterns of password recovery attempts that may indicate enumeration attempts. Organizations should also consider implementing CAPTCHA mechanisms or other anti-automation controls during authentication flows to prevent automated enumeration attacks. Regular security assessments and penetration testing should be conducted to identify similar information disclosure vulnerabilities in other application components and ensure that similar issues do not exist in related systems or third-party integrations that may provide similar attack surfaces.