CVE-2005-0831 in Web Forum
Summary
by MITRE
PHP-Post allows remote attackers to spoof the names of other users by registering with a username containing hex-encoded characters.
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Analysis
by VulDB Data Team • 07/22/2017
The vulnerability described in CVE-2005-0831 affects PHP-Post software and represents a significant authentication and authorization flaw that enables remote attackers to impersonate legitimate users within the system. This issue stems from improper handling of username validation and encoding within the web application's user registration and authentication mechanisms. The vulnerability specifically exploits the way the system processes usernames that contain hex-encoded characters, allowing malicious actors to craft usernames that appear to belong to other users.
The technical flaw manifests when the PHP-Post application fails to properly sanitize or validate user input during the registration process. When users attempt to register with usernames containing hex-encoded characters, the system does not adequately process these inputs to prevent malicious manipulation of user identities. This weakness creates a path for attackers to register accounts using names that are visually similar or identical to existing legitimate users, effectively enabling user spoofing attacks. The vulnerability operates at the application layer and relies on the system's insufficient validation of special characters within user identifiers.
The operational impact of this vulnerability extends beyond simple identity confusion, as it can enable a range of malicious activities including unauthorized access to user accounts, data manipulation, and potential privilege escalation. Attackers can leverage this flaw to create accounts that appear to belong to trusted users, potentially bypassing security controls that rely on user identity verification. This type of vulnerability can be particularly damaging in environments where user authentication is critical for access control, as it undermines the fundamental security principle of user identity verification and can lead to unauthorized system access or data breaches.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms within the PHP-Post application. The system should enforce strict username validation that rejects or properly processes hex-encoded characters and other special sequences that could be used for impersonation. Organizations should implement proper encoding validation routines that ensure user identifiers are normalized and validated against established security policies. Additionally, the application should employ proper access control measures that validate user identities through multiple factors rather than relying solely on username-based authentication. This vulnerability aligns with CWE-20, which describes improper input validation, and could be categorized under ATT&CK technique T1078 for valid accounts, as it enables attackers to operate under false user identities. The remediation process should include thorough code review of authentication mechanisms and implementation of comprehensive user input sanitization protocols to prevent similar encoding-based attacks.