CVE-2006-0604 in phphg Guestbook
Summary
by MITRE
check.php in Hinton Design phphg Guestbook 1.2 does not check the user password when authenticating via cookies, which allows remote attackers to gain unauthorized access.
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Analysis
by VulDB Data Team • 08/04/2017
The vulnerability identified in CVE-2006-0604 affects the phphg Guestbook version 1.2 developed by Hinton Design, specifically within the check.php script responsible for user authentication processes. This flaw represents a critical security weakness that undermines the application's access control mechanisms and creates an avenue for unauthorized system compromise. The vulnerability stems from the application's failure to properly validate user credentials when authentication occurs through cookie-based mechanisms, creating a significant bypass opportunity for malicious actors.
The technical implementation of this vulnerability resides in the authentication logic of the check.php file where the system should verify user credentials against stored password hashes or encrypted values. Instead, the application relies solely on cookie validation without performing the necessary password verification checks that would normally occur during the authentication process. This design flaw allows an attacker who has obtained a valid cookie to bypass the password authentication requirement entirely, effectively granting full access to the guestbook administrative functions without proper authorization. The vulnerability manifests as a missing input validation and authentication control mechanism that should have been implemented to ensure credential integrity.
From an operational perspective, this vulnerability creates severe implications for system security and data integrity within the affected environment. An attacker who successfully exploits this weakness can gain full administrative privileges to the guestbook application, potentially enabling them to modify or delete guestbook entries, access sensitive user data, alter application configuration, and perform other malicious activities. The impact extends beyond simple unauthorized access as it provides a persistent foothold within the system that could be leveraged for further attacks or reconnaissance activities. The vulnerability's remote exploitability means that attackers do not require physical access to the system or local network privileges to take advantage of this flaw.
The weakness aligns with CWE-287, which addresses improper authentication scenarios where systems fail to properly verify user credentials. This vulnerability also maps to several ATT&CK techniques including T1078 for valid accounts and T1566 for credential harvesting, as the flaw essentially allows attackers to use stolen or guessed credentials without proper authentication verification. Organizations should implement immediate mitigations including updating to a patched version of the phphg Guestbook application, implementing proper cookie validation mechanisms, and establishing monitoring for unauthorized access attempts. Additionally, security measures such as secure cookie flags, proper session management, and regular security audits should be implemented to prevent similar vulnerabilities from occurring in other applications. The remediation process should also include disabling cookie-based authentication where password verification is not properly enforced, and ensuring that all authentication mechanisms require proper credential validation regardless of the authentication method used.