CVE-2006-5509 in Burning Book
Summary
by MITRE
Eval injection vulnerability in addentry.php in WoltLab Burning Book 1.1.2 allows remote attackers to execute arbitrary PHP code via crafted POST requests that store PHP code in a database that is later processed by eval, as demonstrated using SQL injection via the n parameter.
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Analysis
by VulDB Data Team • 04/25/2026
The CVE-2006-5509 vulnerability represents a critical server-side code injection flaw in WoltLab Burning Book version 1.1.2 that enables remote attackers to execute arbitrary PHP code through improper input validation and sanitization. This vulnerability specifically affects the addentry.php script which processes user-submitted data and subsequently evaluates it using the dangerous eval() function. The flaw occurs when attackers craft malicious POST requests containing PHP code within the n parameter, which gets stored in the database and later executed during subsequent processing operations. This type of vulnerability falls under the CWE-94 category of Improper Control of Generation of Code, where the application dynamically generates code without proper input validation or sanitization mechanisms.
The technical exploitation of this vulnerability leverages SQL injection techniques combined with code injection principles to bypass normal input validation controls. Attackers can inject malicious PHP code through the n parameter, which gets stored in the database and later processed by the eval() function during script execution. This creates a persistent code execution vector where malicious code becomes part of the application's runtime environment. The vulnerability demonstrates poor input sanitization practices and inadequate parameter validation, allowing attackers to manipulate the application's data processing flow. The use of eval() function in conjunction with unsanitized user input creates an ideal environment for arbitrary code execution attacks, as highlighted by ATT&CK technique T1059.007 for Command and Scripting Interpreter.
The operational impact of this vulnerability is severe as it provides attackers with complete control over the affected server environment. Once exploited, attackers can execute arbitrary commands with the privileges of the web server process, potentially leading to data breaches, system compromise, and further lateral movement within the network. The persistent nature of the vulnerability means that malicious code remains active until the database entries are manually removed or the application is patched. This vulnerability affects the confidentiality, integrity, and availability of the affected system, as attackers can read sensitive data, modify content, and potentially disrupt services. The vulnerability also demonstrates weaknesses in the application's defense-in-depth strategy, as multiple layers of security controls failed to prevent the injection of malicious code.
Mitigation strategies for CVE-2006-5509 require immediate patching of the affected WoltLab Burning Book version 1.1.2 to address the root cause of the vulnerability. Organizations should implement proper input validation and sanitization measures to prevent malicious code from entering the system through user inputs. The use of eval() functions should be eliminated or strictly controlled when processing user-supplied data, as this function creates inherent security risks. Database input should be properly escaped and validated before storage, and parameterized queries should be employed to prevent SQL injection attacks. Additionally, implementing web application firewalls, input filtering mechanisms, and regular security code reviews can help prevent similar vulnerabilities. The vulnerability also highlights the importance of following secure coding practices and adhering to security standards such as OWASP Top 10 and NIST Cybersecurity Framework to prevent injection vulnerabilities. Organizations should also implement monitoring and logging mechanisms to detect unusual activities that may indicate exploitation attempts.