CVE-2006-4122 in Simple one-file guestbook
Summary
by MITRE
Simple one-file guestbook 1.0 and earlier allows remote attackers to bypass authentication and delete guestbook entries via a modified id parameter to guestbook.php.
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Analysis
by VulDB Data Team • 09/22/2017
The vulnerability described in CVE-2006-4122 represents a critical authentication bypass flaw in Simple one-file guestbook versions 1.0 and earlier. This web application suffers from insufficient input validation and improper access control mechanisms that allow malicious actors to manipulate the application's behavior through crafted parameters. The vulnerability specifically targets the guestbook.php script where the id parameter is processed without adequate security checks, creating an exploitable condition that undermines the application's intended access controls.
The technical flaw manifests as a lack of proper parameter validation and authentication verification within the guestbook.php script. When an attacker modifies the id parameter to target specific guestbook entries, the application fails to verify whether the authenticated user has proper authorization to delete the requested entry. This weakness stems from the application's reliance on client-side parameter manipulation without implementing server-side access control validation. The vulnerability falls under the category of insufficient authentication checks and improper input sanitization, which are commonly associated with CWE-285 and CWE-287 categories that address authorization and authentication flaws.
The operational impact of this vulnerability extends beyond simple data manipulation, as it enables unauthorized users to perform destructive actions on the guestbook system. Remote attackers can exploit this flaw to delete legitimate guestbook entries without proper authorization, potentially causing data loss and compromising the integrity of the guestbook records. This vulnerability directly impacts the availability and integrity of information stored within the application, as unauthorized modifications can occur without detection. The attack vector is particularly concerning because it requires no local access or elevated privileges, making it accessible to anyone who can reach the vulnerable web application through network communication.
Security professionals should recognize this vulnerability as a classic example of insecure direct object reference, where the application exposes internal object references to users without proper access control verification. The flaw aligns with ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential harvesting, as the vulnerability enables unauthorized access to application functionality that should require authentication. Organizations should implement proper input validation, authentication verification, and access control mechanisms to prevent such issues. Recommended mitigations include implementing proper session management, validating user permissions before processing delete requests, and sanitizing all input parameters to prevent parameter manipulation attacks.
The vulnerability demonstrates the importance of proper application security design and the necessity of implementing defense-in-depth strategies. Simple applications like guestbooks should not be overlooked in security assessments, as they often serve as entry points for more extensive attacks. This flaw underscores the principle that authentication mechanisms must be robust and that all user inputs should be validated regardless of their source or intended use within the application. The vulnerability also highlights the need for regular security updates and patch management, as this issue was present in versions 1.0 and earlier, indicating a lack of security consideration in the application's development lifecycle.