CVE-2006-2152 in phpBB Advanced Guestbook
Summary
by MITRE
PHP remote file inclusion vulnerability in admin/addentry.php in phpBB Advanced Guestbook 2.4.0 and earlier, when register_globals is enabled, allows remote attackers to include arbitrary files via the phpbb_root_path parameter.
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Analysis
by VulDB Data Team • 06/23/2024
The vulnerability identified as CVE-2006-2152 represents a critical remote file inclusion flaw within the phpBB Advanced Guestbook version 2.4.0 and earlier installations. This security weakness specifically targets the admin/addentry.php script and exploits a fundamental configuration issue that arises when the register_globals PHP directive is enabled. The vulnerability stems from inadequate input validation and sanitization practices within the application's parameter handling mechanisms, creating an exploitable path for malicious actors to execute arbitrary code on the affected system. The flaw operates by accepting unvalidated user input through the phpbb_root_path parameter, which is then used to construct file inclusion operations without proper security checks.
The technical exploitation of this vulnerability requires that the target server has register_globals enabled, a configuration that was common in older PHP installations but considered a security risk. When an attacker can manipulate the phpbb_root_path parameter through HTTP requests, they can inject malicious file paths that will be included by the vulnerable script. This creates a remote code execution scenario where attackers can potentially upload and execute malicious scripts, access sensitive data, or compromise the entire web server. The vulnerability aligns with CWE-94, which describes the improper control of generation of code, and specifically relates to the improper neutralization of special elements used in OS commands. From an attack perspective, this flaw maps to ATT&CK technique T1190, which covers the exploitation of remote services through vulnerabilities in web applications.
The operational impact of CVE-2006-2152 extends beyond simple code execution, as it provides attackers with persistent access to the compromised system and can lead to complete system takeover. Once exploited, attackers can establish backdoors, exfiltrate database contents, modify web content, or use the compromised server for further attacks against other systems. The vulnerability's exploitation is particularly dangerous because it requires minimal user interaction and can be automated, making it a preferred target for mass exploitation campaigns. Organizations running affected phpBB Advanced Guestbook versions face significant risk of data breaches, service disruption, and potential regulatory compliance violations. The vulnerability also demonstrates the importance of proper input validation and the dangers of legacy configuration settings that remain enabled in production environments.
Mitigation strategies for this vulnerability require immediate action to either disable the register_globals directive in PHP configuration or implement proper input validation within the application code. System administrators should upgrade to phpBB Advanced Guestbook version 2.4.1 or later, which contains patches addressing this specific vulnerability. Additionally, implementing web application firewalls, input sanitization, and output encoding can provide additional layers of protection. Security monitoring should include detection of suspicious file inclusion patterns and unauthorized access attempts. The vulnerability also highlights the necessity of regular security audits, proper configuration management, and maintaining up-to-date software versions. Organizations should conduct comprehensive vulnerability assessments to identify similar flaws in other applications and ensure that legacy features are properly secured or disabled to prevent exploitation through similar attack vectors.