CVE-2007-0926 in guestbook
Summary
by MITRE
The dologin function in guestbook.php in KvGuestbook 1.0 Beta allows remote attackers to gain administrative privileges, probably via modified $mysql[ pass ] and $gbpass variables.
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Analysis
by VulDB Data Team • 08/19/2018
The vulnerability identified as CVE-2007-0926 resides within the KvGuestbook 1.0 Beta web application, specifically in the dologin function located within the guestbook.php file. This represents a critical authentication bypass flaw that directly impacts the application's security model and user access controls. The vulnerability stems from improper input validation and sanitization mechanisms within the login processing logic, allowing malicious actors to manipulate session variables and escalate their privileges from regular guest users to administrative accounts. The flaw specifically targets the mysql pass and gbpass variables, which are crucial for authentication verification within the guestbook system. This vulnerability aligns with CWE-287, which addresses improper authentication issues in web applications, and demonstrates how insufficient validation of user-supplied input can lead to privilege escalation.
The technical exploitation of this vulnerability occurs through manipulation of the $mysql[pass] and $gbpass variables, which are typically used to store password hashes or authentication tokens during the login process. Attackers can craft specially formatted requests that modify these variables in ways that bypass the normal authentication checks implemented by the application. The vulnerability essentially allows for arbitrary code execution within the authentication context, enabling unauthorized users to assume administrative roles without proper credentials. This type of flaw falls under the ATT&CK technique T1078 which covers Valid Accounts and privilege escalation through compromised authentication mechanisms. The weakness in the application's input handling creates a direct path for attackers to manipulate the application's internal state and gain elevated privileges.
The operational impact of this vulnerability is severe and far-reaching within the context of web application security. Successful exploitation allows attackers to gain full administrative control over the guestbook application, which typically includes the ability to modify or delete guestbook entries, access sensitive user data, manipulate application configuration settings, and potentially use the compromised system as a foothold for further attacks within the network. The vulnerability affects not just the guestbook functionality but also represents a broader security failure in the application's architecture that could expose other system components to similar threats. Organizations running KvGuestbook 1.0 Beta are at significant risk of data breaches, content tampering, and unauthorized access to user information, as the vulnerability provides a direct pathway to administrative access without requiring legitimate credentials. This type of privilege escalation vulnerability can also serve as a stepping stone for attackers to conduct more sophisticated attacks within the network infrastructure.
Mitigation strategies for CVE-2007-0926 must address both the immediate security flaw and the underlying architectural issues that enabled the vulnerability. The most effective approach involves implementing proper input validation and sanitization for all user-supplied data, particularly within authentication functions where variables like $mysql[pass] and $gbpass are processed. Developers should employ parameterized queries and strict type checking to prevent manipulation of critical variables. Additionally, the application should implement robust authentication mechanisms that do not rely on client-side variable manipulation for privilege determination. Security measures should include input filtering that prevents modification of critical session variables, implementation of secure password handling practices, and regular security audits to identify similar vulnerabilities. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts. The vulnerability highlights the importance of following secure coding practices and adhering to security standards such as those outlined in the OWASP Top Ten project, which emphasizes proper authentication and session management as fundamental security requirements for web applications.