CVE-2019-6798 in phpMyAdmin
Summary
by MITRE
An issue was discovered in phpMyAdmin before 4.8.5. A vulnerability was reported where a specially crafted username can be used to trigger a SQL injection attack through the designer feature.
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Analysis
by VulDB Data Team • 05/06/2020
The vulnerability identified as CVE-2019-6798 represents a critical SQL injection flaw within phpMyAdmin versions prior to 4.8.5, specifically affecting the designer feature functionality. This issue stems from inadequate input validation and sanitization mechanisms that fail to properly handle maliciously crafted usernames, creating an avenue for attackers to execute unauthorized database operations. The vulnerability exists within the application's user authentication and authorization processing pipeline, where user-provided identifiers are directly incorporated into SQL query construction without proper escaping or parameterization. Security researchers have classified this as a SQL injection vulnerability that aligns with CWE-89, which specifically addresses improper neutralization of special elements used in SQL commands, making it a direct descendant of the well-known OWASP Top Ten vulnerability category.
The technical exploitation of this vulnerability occurs through the designer feature, which allows users to create and modify database schema relationships and visual representations. When a specially crafted username containing malicious SQL payloads is submitted, the application fails to adequately sanitize this input before incorporating it into backend database queries. This flaw enables attackers to manipulate the SQL execution flow and potentially execute arbitrary database commands, including but not limited to data extraction, modification, or deletion operations. The vulnerability's impact is amplified by the fact that it operates within the context of authenticated users, meaning that an attacker must first obtain valid credentials to exploit this weakness, though the privilege escalation potential remains significant once the injection vector is established.
The operational impact of CVE-2019-6798 extends beyond simple data theft, as successful exploitation can lead to complete database compromise and potential lateral movement within affected environments. Attackers leveraging this vulnerability can gain unauthorized access to sensitive information stored within database systems, potentially including user credentials, personal data, financial records, and proprietary business information. The attack surface is particularly concerning in environments where phpMyAdmin serves as a primary database administration interface, as it often provides elevated privileges and direct access to underlying database structures. This vulnerability also aligns with ATT&CK technique T1078.004, which covers valid accounts with compromised credentials, and T1046, representing network service scanning that may be employed to identify vulnerable installations.
Organizations affected by this vulnerability should prioritize immediate patching of all phpMyAdmin installations to version 4.8.5 or later, as this update includes comprehensive input validation fixes and improved SQL query sanitization mechanisms. Additional mitigations should include implementing network segmentation to limit access to phpMyAdmin interfaces, enforcing strong authentication controls with multi-factor authentication, and monitoring for suspicious login patterns or unusual database activity that may indicate exploitation attempts. Security teams should also conduct comprehensive vulnerability assessments to identify all systems running vulnerable versions of phpMyAdmin and ensure proper access controls are implemented to restrict administrative functions to authorized personnel only. The remediation process must include thorough testing of the updated software to ensure that all functionality remains intact while addressing the identified security weakness through proper code review and input validation implementation practices.