CVE-2005-2183 in PhpXmail
Summary
by MITRE
class.xmail.php in PhpXmail 0.7 through 1.1 does not properly handle large passwords, which prevents an error message from being returned and allows remote attackers to bypass authentication and gain unauthorized access.
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Analysis
by VulDB Data Team • 07/10/2018
The vulnerability identified as CVE-2005-2183 resides within the class.xmail.php component of PhpXmail versions 0.7 through 1.1, representing a critical authentication bypass flaw that fundamentally undermines the security posture of affected systems. This issue stems from improper handling of password length validation within the email processing framework, creating a scenario where attackers can exploit the system's failure to properly validate input parameters. The vulnerability manifests when users attempt to authenticate with excessively long passwords, causing the system to fail silently rather than returning appropriate error messages that would normally indicate invalid input or authentication failure.
The technical implementation of this flaw involves the application's authentication routine failing to properly validate password length constraints before processing authentication requests. When a password exceeds the system's expected length limits, the validation mechanism does not trigger the appropriate error handling procedures, instead allowing the malformed input to proceed through the authentication pipeline. This failure in input validation creates a condition where the system's authentication logic becomes bypassed, enabling unauthorized access through what should have been rejected authentication attempts. The vulnerability specifically relates to inadequate boundary checking and input sanitization within the email handling component, where password validation does not properly account for maximum length constraints that would normally prevent such scenarios.
From an operational perspective, this vulnerability presents a significant risk to systems utilizing PhpXmail within their email infrastructure, particularly those that rely on the application for user authentication or email processing services. Attackers can exploit this flaw by submitting authentication requests with passwords that exceed the system's accepted length limits, effectively bypassing the authentication mechanism entirely without triggering any error responses that would normally alert system administrators to potential unauthorized access attempts. The silent failure of the authentication process creates a false sense of security while simultaneously allowing unauthorized individuals to gain access to protected email services and potentially sensitive information processed through the affected system.
The impact of this vulnerability aligns with CWE-20, which describes improper input validation, and specifically relates to CWE-254, representing weaknesses in input handling that can lead to authentication bypass scenarios. This flaw can be categorized under the ATT&CK framework as T1110.003, representing Brute Force/Password Guessing techniques, where the vulnerability enables attackers to bypass authentication mechanisms through improper handling of valid input parameters. The vulnerability also demonstrates characteristics of T1078.004, which covers valid accounts used for lateral movement, as unauthorized access can be achieved through legitimate authentication mechanisms that have been subverted by improper input handling.
Mitigation strategies for CVE-2005-2183 should prioritize immediate patching of affected PhpXmail installations to version 1.2 or later, which contains the necessary fixes for proper password length validation. System administrators should implement comprehensive input validation measures that enforce strict boundary checking for all authentication parameters, including password length constraints that prevent excessively long inputs from being processed. Network monitoring should be enhanced to detect unusual authentication patterns or repeated failed authentication attempts that might indicate exploitation attempts. Additionally, organizations should conduct thorough vulnerability assessments to identify all instances of affected PhpXmail versions and ensure proper configuration of authentication mechanisms to prevent similar issues in other components of their email infrastructure. The implementation of proper error handling and logging procedures will also help detect potential exploitation attempts and provide better visibility into system security events.