CVE-2020-13694 in Community Edition
Summary
by MITRE
In QuickBox Community Edition through 2.5.5 and Pro Edition through 2.1.8, the local www-data user can execute sudo mysql without a password, which means that the www-data user can execute arbitrary OS commands via the mysql -e option.
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Analysis
by VulDB Data Team • 06/02/2020
The vulnerability identified as CVE-2020-13694 affects QuickBox Community Edition versions through 2.5.5 and Pro Edition versions through 2.1.8, representing a critical privilege escalation flaw that directly impacts the security posture of affected systems. This issue stems from improper sudo configuration within the QuickBox application framework, where the www-data user account which typically handles web server operations has been granted passwordless sudo access to the mysql command. The vulnerability classifies under CWE-276 as an insecure file permissions issue, specifically concerning improper privileges for critical system resources, and aligns with ATT&CK technique T1068 which covers privilege escalation through insecure configuration.
The technical exploitation of this vulnerability occurs through the mysql -e command option which allows execution of SQL statements directly from the command line. When the www-data user can execute mysql with sudo privileges without password authentication, an attacker can leverage this access to execute arbitrary operating system commands by crafting malicious SQL statements that invoke system-level operations through mysql's execution capabilities. This creates a direct pathway for attackers to bypass web application security controls and gain elevated system privileges. The flaw essentially transforms the web server's execution environment into a potential command shell, as the mysql client can be used to invoke system commands through various mechanisms including the use of system functions within SQL statements.
The operational impact of this vulnerability is severe and far-reaching, as it allows attackers to escalate privileges from the web server user to root level access without requiring any authentication credentials. This enables comprehensive system compromise including but not limited to data exfiltration, system reconnaissance, persistence establishment, and deployment of additional malicious software. The vulnerability is particularly dangerous because it operates within the trusted web server environment, making detection more difficult and allowing attackers to remain undetected while performing malicious activities. Organizations using QuickBox in production environments face significant risk of unauthorized access, data breaches, and complete system compromise, as the vulnerability provides a straightforward path for privilege escalation that does not require specialized attack techniques or extensive reconnaissance.
Mitigation strategies for CVE-2020-13694 should focus on immediate remediation through proper sudo configuration management and privilege reduction. The primary fix involves removing the passwordless sudo access for the www-data user to the mysql command by modifying the sudoers configuration file to either eliminate the specific sudo rule or require authentication for the mysql command execution. System administrators should implement the principle of least privilege by ensuring that web server accounts have only the minimal permissions necessary for their intended operations. Additionally, organizations should conduct comprehensive security audits of all sudo configurations, implement regular privilege reviews, and deploy monitoring solutions to detect unauthorized sudo usage patterns. The vulnerability highlights the importance of secure configuration management practices and demonstrates how seemingly minor misconfigurations can lead to catastrophic security consequences. Regular security updates and patch management procedures should be enforced to prevent similar issues from occurring in the future, while also implementing network segmentation and access controls to limit the potential impact of such vulnerabilities.