CVE-2006-4785 in Moodle
Summary
by MITRE
SQL injection vulnerability in blog/edit.php in Moodle 1.6.1 and earlier allows remote attackers to execute arbitrary SQL commands via the format parameter as stored in the $blogEntry variable, which is not properly handled by the insert_record function, which calls _adodb_column_sql in the adodb layer (lib/adodb/adodb-lib.inc.php), which does not convert the data type to an int.
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Analysis
by VulDB Data Team • 07/08/2019
The vulnerability described in CVE-2006-4785 represents a critical sql injection flaw within the moodle learning management system version 1.6.1 and earlier. This weakness exists in the blog/edit.php component where user input is improperly sanitized before being processed by the database layer. The vulnerability specifically targets the format parameter which is stored in the $blogEntry variable and subsequently passed through the insert_record function. The flaw demonstrates a classic lack of input validation and proper data type handling that creates an exploitable pathway for malicious actors to execute arbitrary sql commands on the underlying database system.
The technical implementation of this vulnerability stems from the improper handling of data types within the adodb database abstraction layer. When the insert_record function processes the blog entry data, it invokes the _adodb_column_sql function located in lib/adodb/adodb-lib.inc.php. This function fails to properly convert the data type to an integer as required for safe database operations, leaving the system vulnerable to sql injection attacks. The root cause lies in the insufficient sanitization of user-provided data before database insertion, particularly when dealing with parameters that should be strictly numeric but are instead treated as string values.
The operational impact of this vulnerability is severe and far-reaching for organizations utilizing affected moodle installations. Remote attackers can leverage this weakness to bypass authentication mechanisms, extract sensitive user data, modify or delete database records, and potentially gain full control over the database server. The vulnerability affects the core functionality of the blog module, which is commonly used in educational environments for student assignments and collaborative learning. Given that moodle is widely deployed in academic institutions, the potential for widespread compromise increases significantly, as attackers can target multiple organizations simultaneously through the exploitation of this common vulnerability.
Organizations should immediately implement multiple layers of mitigation strategies to address this vulnerability. The primary remediation involves upgrading to moodle version 1.6.2 or later where the vulnerability has been patched. Additionally, administrators should implement proper input validation and sanitization procedures, particularly for parameters that should be numeric. The use of parameterized queries and prepared statements should be enforced throughout the application codebase to prevent similar issues. Network-based mitigations including firewall rules and web application firewalls can provide additional protection, though they should not be considered a substitute for proper code-level fixes. Security monitoring and logging should be enhanced to detect potential exploitation attempts, and regular security assessments should be conducted to identify similar vulnerabilities in other components of the system. This vulnerability aligns with CWE-89 sql injection and follows patterns commonly seen in ATT&CK technique T1190 exploitation of remote services, highlighting the importance of proper input handling and data type validation in web application security.