CVE-2006-0075 in phpBook
Summary
by MITRE
Direct static code injection vulnerability in phpBook 1.3.2 and earlier allows remote attackers to execute arbitrary PHP code via the e-mail field (mail variable) in a new message, which is written to a PHP file.
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Analysis
by VulDB Data Team • 07/17/2018
The vulnerability identified as CVE-2006-0075 represents a critical direct static code injection flaw within phpBook version 1.3.2 and earlier installations. This vulnerability resides in the message submission functionality where user input from the email field is directly incorporated into PHP code without proper sanitization or validation. The flaw manifests when attackers submit malicious code through the mail variable which gets written to a PHP file, effectively creating a persistent backdoor within the application's file system.
The technical implementation of this vulnerability stems from improper input validation and output encoding practices within the phpBook application. When users submit messages through the web interface, the email field value is concatenated directly into PHP code segments that are subsequently saved to disk. This static code injection pattern violates fundamental security principles and creates an environment where arbitrary PHP code execution becomes possible. The vulnerability operates under CWE-94, which classifies it as a "Improper Control of Generation of Code" where the application generates code based on user-controllable data without adequate sanitization.
The operational impact of this vulnerability extends far beyond simple code injection, as it provides attackers with complete remote code execution capabilities on the affected server. Once exploited, attackers can execute malicious PHP code with the privileges of the web server process, potentially leading to full system compromise. The vulnerability enables attackers to perform various malicious activities including data exfiltration, privilege escalation, and establishment of persistent access points. According to ATT&CK framework, this vulnerability maps to T1059.007 for "Command and Scripting Interpreter: PHP" and T1078 for "Valid Accounts" as attackers can leverage the compromised system to maintain persistent access.
The exploitation process typically involves crafting a malicious email address containing PHP payload code that gets executed when the vulnerable application processes the message. This creates a persistent threat vector where attackers can upload backdoors, modify existing files, or establish reverse shells. The vulnerability affects the application's core functionality by allowing attackers to manipulate the message handling system and gain unauthorized access to the underlying file system. Security professionals should note that this vulnerability represents a classic example of unsafe direct object reference and improper input handling that remains relevant in modern security assessments.
Mitigation strategies for CVE-2006-0075 require immediate application patching to the latest phpBook version that addresses the code injection vulnerability. Organizations should implement proper input validation and sanitization measures to prevent malicious code from being written to PHP files. Additionally, the web server should be configured with restricted file permissions to minimize the impact of successful exploitation. Regular security audits and input validation testing should be implemented to prevent similar vulnerabilities from emerging in other application components. The vulnerability demonstrates the critical importance of proper code review processes and input sanitization in preventing remote code execution attacks that can compromise entire web applications.