CVE-2009-2336 in WordPress
Summary
by MITRE
The forgotten mail interface in WordPress and WordPress MU before 2.8.1 exhibits different behavior for a password request depending on whether the user account exists, which allows remote attackers to enumerate valid usernames. NOTE: the vendor reportedly disputes the significance of this issue, indicating that the behavior exists for "user convenience."
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Analysis
by VulDB Data Team • 12/03/2024
The vulnerability described in CVE-2009-2336 represents a classic account enumeration flaw that affects WordPress and WordPress MU versions prior to 2.8.1. This security weakness resides in the forgotten password functionality of the content management system, where the application's response behavior varies based on whether a requested username exists in the system. The issue stems from the implementation of the password recovery interface, which provides different error messages or responses to users attempting to reset passwords for accounts that do exist versus those that do not exist within the WordPress installation. This inconsistent behavior creates a predictable pattern that malicious actors can exploit to determine which usernames are valid within the system, effectively enabling account enumeration attacks.
The technical nature of this vulnerability aligns with CWE-204, which describes weaknesses related to information exposure through inconsistent error handling. The flaw operates at the application logic level where the system's response to user input differs based on internal state conditions. When an attacker submits a username that exists in the WordPress database, the system typically provides a success message or proceeds to the password reset process, whereas submitting a non-existent username often results in a different error message or behavior. This differential response creates a timing or behavioral signature that attackers can use to systematically test usernames and identify valid accounts within the WordPress installation. The vulnerability specifically targets the authentication and user management components of the WordPress platform, exploiting the lack of consistent error handling in the password recovery workflow.
The operational impact of this vulnerability extends beyond simple username enumeration, as it provides attackers with a foundational step for more sophisticated attacks including credential stuffing, brute force attempts, and social engineering operations. Once valid usernames are identified through this enumeration process, attackers can focus their efforts on exploiting weak passwords or attempting to gain unauthorized access to legitimate user accounts. The vulnerability affects all WordPress installations using versions 2.8.0 and earlier, including WordPress MU, making it a widespread concern for organizations running these outdated systems. The impact is particularly significant for WordPress installations that host sensitive content or serve as platforms for user-generated content where account compromise could lead to data breaches, content manipulation, or unauthorized administrative access. Security researchers have noted that this type of information disclosure vulnerability can be particularly dangerous when combined with other attack vectors, as it reduces the attack surface required for successful compromise.
The mitigation strategy for CVE-2009-2336 involves immediate upgrading to WordPress version 2.8.1 or later, where the password recovery functionality was modified to provide consistent responses regardless of whether the requested username exists in the system. Organizations should also implement additional security controls such as account lockout mechanisms, rate limiting on password reset requests, and monitoring for suspicious login patterns. The vulnerability demonstrates the importance of consistent error handling in security-sensitive applications and highlights the need for security considerations in user interface design. From an ATT&CK framework perspective, this vulnerability relates to techniques involving credential access and reconnaissance, specifically T1110 for Brute Force and T1566 for Phishing, as it enables attackers to gather information needed for more targeted attacks. Organizations should also consider implementing multi-factor authentication as an additional defense mechanism, as even if username enumeration occurs, the presence of additional authentication factors can significantly reduce the risk of successful account compromise. The incident underscores the critical importance of keeping software updated and maintaining proper security configurations to prevent attackers from exploiting known vulnerabilities that can provide footholds for more extensive compromise operations.