CVE-2006-5500 in XchangeBoard
Summary
by MITRE
Multiple SQL injection vulnerabilities in the checkUser function in inc/DBInterface.php in XchangeBoard 1.70 and earlier, when magic_quotes_gpc is disabled, allow remote attackers to execute arbitrary SQL commands via the (1) userNick or (2) password parameters. NOTE: the provenance of this information is unknown; the details are obtained from third party information.
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Analysis
by VulDB Data Team • 04/25/2026
The vulnerability described in CVE-2006-5500 represents a critical SQL injection flaw within the XchangeBoard 1.70 software suite, specifically targeting the checkUser function located in the inc/DBInterface.php file. This vulnerability occurs under specific conditions where the PHP configuration parameter magic_quotes_gpc is disabled, creating an environment where user input is not automatically escaped before being processed in database queries. The flaw affects two primary parameters within the authentication mechanism: userNick and password, which are commonly used for user identification and verification processes. The vulnerability classification aligns with CWE-89, which defines SQL injection as a condition where an application fails to properly sanitize user input before incorporating it into SQL commands, thereby allowing attackers to manipulate database operations through malicious input.
The operational impact of this vulnerability extends beyond simple data theft, as it provides remote attackers with the capability to execute arbitrary SQL commands against the underlying database system. When magic_quotes_gpc is disabled, the application fails to implement automatic escaping of special characters in user input, leaving the database interface directly vulnerable to malicious SQL payloads. Attackers can exploit this weakness by crafting specially formatted input for the userNick or password fields that, when processed by the checkUser function, alter the intended SQL query structure. This could potentially lead to unauthorized database access, data modification, deletion of critical information, or even complete database compromise. The vulnerability exists at the application layer and does not require any local privileges, making it particularly dangerous as it can be exploited remotely over the network.
The exploitation of this vulnerability demonstrates a fundamental flaw in input validation and sanitization practices within the XchangeBoard application. The checkUser function, which serves as a critical authentication mechanism, fails to implement proper parameter binding or input sanitization techniques that would normally protect against such attacks. According to ATT&CK framework, this represents a technique categorized under T1190 - Exploit Public-Facing Application, where adversaries target web applications for initial access. The vulnerability also correlates with ATT&CK technique T1071.004 - Application Layer Protocol: DNS, as attackers might use DNS tunneling to bypass network restrictions while exploiting this weakness. Organizations using XchangeBoard versions 1.70 or earlier face significant risk exposure, particularly in environments where the magic_quotes_gpc setting is disabled, which was common in many production PHP configurations at the time of this vulnerability's discovery. The lack of proper input validation in authentication mechanisms creates a direct pathway for attackers to bypass user authentication entirely or gain elevated privileges within the database system.
Mitigation strategies for this vulnerability should focus on immediate remediation through input validation and parameterized queries. The most effective immediate solution involves implementing proper parameter binding or prepared statements in the DBInterface.php file, which would prevent malicious SQL code from being executed regardless of the magic_quotes_gpc setting. Additionally, organizations should ensure that magic_quotes_gpc is properly configured or implement comprehensive input sanitization routines that escape special characters before database processing. The application should also implement proper error handling to prevent information disclosure that could aid attackers in further exploitation attempts. Long-term security improvements should include regular security audits, input validation frameworks, and adherence to secure coding practices as recommended by OWASP Top Ten and NIST cybersecurity guidelines. Organizations should also consider implementing web application firewalls to detect and block common SQL injection patterns, though this represents a defensive measure rather than a primary fix for the underlying vulnerability.