CVE-2020-18888 in puppyCMS
Summary
by MITRE • 05/07/2021
Arbitrary File Deletion vulnerability in puppyCMS v5.1 allows remote malicious attackers to delete the file/folder via /admin/functions.php.
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Analysis
by VulDB Data Team • 05/09/2021
The CVE-2020-18888 vulnerability represents a critical arbitrary file deletion flaw in puppyCMS version 5.1 that exposes the content management system to remote exploitation. This vulnerability specifically affects the administrative functions.php endpoint, which serves as a critical interface for system management operations. The flaw allows unauthenticated attackers to execute malicious file deletion commands against the target system, potentially leading to complete system compromise or data loss. The vulnerability exists due to insufficient input validation and access control mechanisms within the file management functions of the CMS administration panel, creating a direct path for remote attackers to manipulate the file system.
This technical weakness stems from improper sanitization of user-supplied input parameters passed to the file deletion functions within the administrative interface. The vulnerability falls under the category of insecure direct object reference and lacks proper authorization checks, enabling attackers to specify arbitrary file paths for deletion. The flaw is particularly dangerous because it operates without requiring authentication, making it accessible to anyone who can reach the vulnerable endpoint. The administrative functions.php file serves as the primary attack surface, where attackers can manipulate parameters to target system files, configuration files, or even critical application components. This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and represents a classic example of path traversal exploitation techniques.
The operational impact of CVE-2020-18888 extends beyond simple file deletion to encompass complete system compromise and data destruction. Attackers can leverage this vulnerability to remove critical application files, configuration settings, or even system executables that could render the CMS inoperable. The potential for cascading effects includes the removal of backup files, database connection scripts, or security-related components that could prevent system recovery. Additionally, the vulnerability could enable attackers to delete log files or security monitoring components, effectively removing evidence of their activities and compromising system integrity. Organizations running vulnerable puppyCMS installations face significant risk of service disruption, data loss, and potential regulatory compliance violations. The impact is further amplified by the fact that this vulnerability affects the administrative functions, which means attackers could potentially gain persistent access to system resources or cause denial of service conditions.
Mitigation strategies for CVE-2020-18888 should prioritize immediate patching of the vulnerable puppyCMS version 5.1 to address the input validation and access control deficiencies. Organizations should implement network-level restrictions to limit access to administrative endpoints, particularly the functions.php file, through firewall rules or access control lists. The implementation of proper input sanitization and parameter validation within the application code is essential to prevent malicious path manipulation. Security measures should include disabling unnecessary administrative functions, implementing strong authentication mechanisms, and conducting regular security audits of CMS components. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting the vulnerable endpoint. The vulnerability demonstrates the importance of proper access control implementation and input validation, aligning with ATT&CK techniques related to privilege escalation and persistence through file system manipulation. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other CMS components or third-party integrations that could present analogous attack vectors.