CVE-2008-2018 in PHPizabi
Summary
by MITRE
The AssignUser function in template.class.php in PHPizabi 0.848b C1 HFP3 performs unsafe macro expansions on strings delimited by { and } characters, which allows remote authenticated users to obtain sensitive information via a comment containing a macro, as demonstrated by a "{user.password}" comment in the profile of the admin user.
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability identified as CVE-2008-2018 resides within the PHPizabi content management system version 0.848b C1 HFP3, specifically within the template.class.php file's AssignUser function. This flaw represents a classic case of unsafe template macro expansion that occurs when user-controllable input is processed without proper sanitization or validation. The vulnerability manifests when strings delimited by curly braces { and } are processed, creating an environment where arbitrary macro expressions can be executed within the template parsing context. The issue is particularly concerning because it affects authenticated users who can leverage this functionality to extract sensitive information from the system.
The technical implementation of this vulnerability exploits the template engine's handling of user-provided data through macro substitution mechanisms. When a user submits content containing macro expressions such as {user.password}, the system processes these expressions without adequate security controls, allowing the macro expansion to retrieve and display sensitive user information including password hashes or other system credentials. This represents a direct violation of information disclosure principles and demonstrates a failure in input validation and sanitization. The vulnerability operates at the application layer and requires authentication to exploit, making it a privilege escalation issue within the context of the application's access controls.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with potential access to credentials that could be used for further compromise of the system. Attackers can craft malicious comments or profile entries that contain macro expressions designed to extract specific user data, particularly targeting administrative accounts where the most sensitive information is stored. This vulnerability can be exploited to harvest authentication tokens, password hashes, or other critical system information that could enable more sophisticated attacks including account takeover or privilege escalation. The exploitation is particularly dangerous because it can be performed through seemingly benign user interface elements such as profile comments or forum posts.
Security mitigations for this vulnerability should focus on implementing proper input sanitization and template security controls within the PHPizabi application. The most effective approach involves modifying the template engine to prevent macro expansion within user-controllable input fields, implementing strict validation of macro expressions, and ensuring that sensitive data cannot be accessed through template substitution mechanisms. Organizations should also implement proper access controls and audit user activities related to profile modifications and comment submissions. This vulnerability aligns with CWE-20, which describes improper input validation, and represents a clear violation of the principle of least privilege as outlined in the ATT&CK framework's credential access techniques. The fix requires comprehensive review and restriction of macro processing capabilities, particularly in contexts where user input is involved, to prevent unauthorized information disclosure.