CVE-2025-6720 in Vchasno Kasa Plugin
Summary
by MITRE • 07/19/2025
The Vchasno Kasa plugin for WordPress is vulnerable to unauthorized loss of data due to a missing capability check on the clear_all_log() function in all versions up to, and including, 1.0.3. This makes it possible for unauthenticated attackers to clear log files.
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Analysis
by VulDB Data Team • 07/19/2025
The vulnerability identified as CVE-2025-6720 affects the Vchasno Kasa plugin for WordPress, a payment processing solution widely used in Ukrainian e-commerce environments. This security flaw represents a critical weakness in the plugin's access control mechanisms, specifically targeting the clear_all_log() function that handles administrative log file operations. The vulnerability exists in all versions up to and including 1.0.3, indicating a long-standing issue that has not been addressed in the plugin's development lifecycle.
The technical flaw stems from the absence of proper capability checks within the clear_all_log() function, which should require administrative privileges to execute. This missing validation allows unauthenticated attackers to exploit the function directly through HTTP requests, bypassing the normal WordPress authentication and authorization processes. The function's design does not verify whether the requesting user possesses sufficient privileges to perform log clearing operations, creating an arbitrary code execution vector that can be leveraged for data loss attacks. This weakness aligns with CWE-284, which addresses improper access control issues in software systems, specifically the failure to enforce proper authorization checks.
The operational impact of this vulnerability extends beyond simple data loss, as it enables attackers to disrupt system operations and potentially cover their tracks during malicious activities. When unauthorized parties can clear log files, they eliminate crucial forensic evidence that would normally help identify intrusion attempts, track user activities, and maintain system integrity. The vulnerability's exploitation can result in complete loss of audit trails, making it extremely difficult for system administrators to detect and respond to security incidents effectively. This capability also facilitates persistent attacks by allowing adversaries to remove evidence of their presence and activities within the WordPress environment.
From a threat modeling perspective, this vulnerability maps directly to several ATT&CK techniques including T1070.004 (Indicator Removal on Host: File Deletion) and T1566.002 (Phishing: Spearphishing Attachment) as attackers can use this weakness to clear logs after successful exploitation. The vulnerability also represents a privilege escalation vector that can be combined with other attacks to create more comprehensive compromise scenarios. Organizations using the Vchasno Kasa plugin are particularly vulnerable because the plugin's functionality directly relates to financial transactions and sensitive data handling, making the potential impact of log manipulation significantly more severe.
The recommended mitigation strategy involves immediate plugin updates to versions that include proper capability checks and authentication enforcement. System administrators should also implement additional security measures such as web application firewalls, rate limiting for administrative endpoints, and enhanced monitoring of log file access patterns. Regular security audits should verify that all WordPress plugins implement proper access controls, with particular attention to functions that modify system state or data integrity. Organizations should consider implementing automated patch management systems to ensure timely deployment of security updates and maintain detailed inventory of all installed plugins to prevent similar vulnerabilities from remaining undetected. The vulnerability demonstrates the critical importance of proper input validation and access control implementation in web applications, particularly those handling sensitive financial data and user information.