CVE-2021-41729 in BaiCloud-cms
Summary
by MITRE • 09/30/2021
BaiCloud-cms v2.5.7 is affected by an arbitrary file deletion vulnerability, which allows an attacker to delete arbitrary files on the server through /user/ppsave.php.
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Analysis
by VulDB Data Team • 10/04/2021
The vulnerability identified as CVE-2021-41729 affects BaiCloud-cms version 2.5.7 and represents a critical arbitrary file deletion flaw that exposes servers to unauthorized file removal operations. This vulnerability exists within the user management functionality of the content management system, specifically through the /user/ppsave.php endpoint which lacks proper input validation and access control mechanisms. The flaw allows remote attackers to manipulate the application's file handling processes and execute destructive operations against arbitrary files on the target server.
The technical implementation of this vulnerability stems from insufficient sanitization of user-supplied input parameters within the ppsave.php script. When users submit data through the affected interface, the application fails to properly validate or sanitize the file paths and names provided in the request parameters. This absence of proper input validation creates an opportunity for attackers to inject malicious file paths that bypass normal file access controls and directory restrictions. The vulnerability manifests when the application processes user data without adequate authorization checks, allowing any authenticated user to potentially delete critical system files, configuration files, or other sensitive data stored on the server.
The operational impact of this vulnerability extends beyond simple file deletion capabilities and represents a severe threat to system integrity and availability. Attackers can leverage this flaw to remove critical application files, configuration data, or even system binaries that could lead to complete application failure or system compromise. The vulnerability can be exploited to delete log files, backup archives, user data, or sensitive configuration files that could result in data loss, service disruption, or provide attackers with additional attack vectors. Furthermore, the ability to remove system files could potentially lead to privilege escalation or enable attackers to establish persistence within the compromised environment.
Security professionals should consider this vulnerability in the context of the CWE-22 weakness category, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks. The ATT&CK framework categorizes this type of vulnerability under the T1059.007 technique, which involves the execution of malicious code through web shell or command injection methods, and potentially T1486 for data destruction activities. Organizations should implement immediate mitigations including input validation controls, proper access control enforcement, and restricting file operations to authorized users only. The recommended security measures include implementing parameterized queries, enforcing strict file path validation, implementing proper authentication and authorization checks, and conducting regular security audits of web application interfaces. Additionally, network segmentation and intrusion detection systems should be deployed to monitor for suspicious file deletion activities and unauthorized access attempts to user management interfaces.
This vulnerability highlights the importance of secure coding practices and proper input validation in web applications. The flaw demonstrates how seemingly minor implementation oversights in file handling operations can lead to catastrophic consequences for system security and data integrity. Organizations using BaiCloud-cms should prioritize immediate patching or mitigation strategies to prevent exploitation of this arbitrary file deletion vulnerability and maintain the overall security posture of their web applications.