CVE-2021-20714 in WP Fastest Cache
Summary
by MITRE • 04/27/2021
Directory traversal vulnerability in WP Fastest Cache versions prior to 0.9.1.7 allows a remote attacker with administrator privileges to delete arbitrary files on the server via unspecified vectors.
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Analysis
by VulDB Data Team • 05/02/2021
The vulnerability identified as CVE-2021-20714 represents a critical directory traversal flaw within the WP Fastest Cache plugin for WordPress systems. This security weakness affects versions prior to 0.9.1.7 and stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data. The vulnerability specifically manifests when the plugin processes file operations, allowing malicious actors to manipulate file paths through crafted input parameters that bypass normal access controls.
The technical implementation of this directory traversal vulnerability exposes the underlying system to arbitrary file deletion attacks through unspecified vectors within the plugin's file handling mechanisms. Attackers with administrator privileges can exploit this weakness to navigate beyond the intended directory boundaries and execute destructive operations on critical server files. The vulnerability operates at the application level and leverages the trust relationship between the authenticated user and the web application to escalate privileges and gain unauthorized access to the file system.
From an operational impact perspective, this vulnerability creates significant risk for WordPress installations utilizing the affected plugin version. The ability to delete arbitrary files compromises system integrity and can result in complete service disruption, data loss, and potential system compromise. The vulnerability is particularly dangerous because it requires only administrator-level access, which is often considered a trusted privilege level within web applications. Once exploited, attackers can remove critical system files, plugin components, or even the entire WordPress installation, leading to complete system outages and potential data recovery challenges.
The vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. This classification indicates that the flaw stems from insufficient validation of file paths and inadequate restrictions on file system access. Additionally, the attack vector follows patterns consistent with ATT&CK technique T1059.001, which involves executing malicious code through command and scripting interpreters, as the directory traversal enables unauthorized file system operations that can facilitate further compromise. Organizations should implement immediate remediation measures by upgrading to WP Fastest Cache version 0.9.1.7 or later, which contains the necessary patches to address this vulnerability and prevent exploitation attempts.
Mitigation strategies should include comprehensive monitoring of file system changes, implementation of web application firewalls to detect suspicious path traversal patterns, and regular security assessments of WordPress plugins to identify similar vulnerabilities. System administrators should also establish robust backup procedures and access control policies to minimize the potential impact of such attacks. The vulnerability demonstrates the critical importance of maintaining up-to-date software components and implementing defense-in-depth strategies to protect against sophisticated exploitation techniques targeting content management systems.