CVE-2018-9331 in zzcms
Summary
by MITRE
An issue was discovered in zzcms 8.2. user/adv.php allows remote attackers to delete arbitrary files via directory traversal sequences in the oldimg parameter. This can be leveraged for database access by deleting install.lock.
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Analysis
by VulDB Data Team • 01/23/2020
The vulnerability identified as CVE-2018-9331 affects zzcms version 8.2 and represents a critical directory traversal flaw in the user/adv.php script. This weakness allows remote attackers to manipulate file deletion operations through the oldimg parameter, enabling them to navigate beyond the intended directory structure and target arbitrary files on the server. The vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly restrict file path manipulation attempts. According to CWE-22, this corresponds to a directory traversal attack where an attacker can access files and directories outside the intended scope through manipulation of input parameters. The flaw specifically exploits the lack of proper path validation in the file deletion functionality, allowing attackers to construct malicious paths that bypass normal access controls.
The operational impact of this vulnerability extends beyond simple file deletion capabilities and creates significant security risks for affected systems. Attackers can leverage this weakness to delete critical system files including the install.lock file, which typically serves as a mechanism to prevent unauthorized access to database configuration and installation procedures. When the install.lock file is removed, it can potentially expose database credentials, configuration files, and other sensitive information that would normally be protected by the installation lock mechanism. This opens the door for further exploitation including database access, data exfiltration, and potential system compromise. The vulnerability aligns with ATT&CK technique T1078 which covers legitimate credentials and T1566 which covers credential access through manipulation of system files.
The security implications of CVE-2018-9331 are particularly severe because it combines multiple attack vectors into a single exploit chain. The directory traversal component allows for arbitrary file deletion, while the specific targeting of install.lock creates a pathway to database access and configuration exposure. This vulnerability demonstrates poor input validation practices and highlights the importance of implementing proper path restriction mechanisms. Organizations using zzcms 8.2 should consider immediate remediation through patch updates from the vendor, while also implementing network-based mitigations such as web application firewalls that can detect and block directory traversal patterns. The flaw also underscores the need for proper access controls and file permission management to prevent unauthorized file operations even when directory traversal attacks are blocked. Security teams should also monitor for potential exploitation attempts through log analysis and implement comprehensive vulnerability management processes to address similar issues in other components of their web applications.