CVE-2022-1001 in WP Downgrade Plugin
Summary
by MITRE • 04/18/2022
The WP Downgrade WordPress plugin before 1.2.3 only perform client side validation of its "WordPress Target Version" settings, but does not sanitise and escape it server side, allowing high privilege users such as admin to perform Cross-Site attacks even when the unfiltered_html capability is disallowed
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Analysis
by VulDB Data Team • 04/21/2022
The vulnerability identified as CVE-2022-1001 affects the WP Downgrade WordPress plugin version 1.2.2 and earlier, representing a critical security flaw that undermines the plugin's validation mechanisms. This issue stems from a fundamental design oversight where the plugin relies exclusively on client-side validation for its "WordPress Target Version" configuration setting while completely neglecting server-side sanitization and escaping procedures. The vulnerability creates a dangerous scenario where administrators can manipulate the target version parameter through the plugin's interface without proper security checks being enforced at the server level.
The technical flaw manifests as a failure to implement proper input validation and sanitization practices, specifically violating security principles outlined in CWE-116 which addresses improper encoding or escaping of output. The plugin's architecture fails to sanitize user-supplied input data before processing it, allowing maliciously crafted version strings to be submitted through the administration interface. This weakness enables attackers with administrator privileges to inject malicious code or manipulate the downgrade process in ways that could compromise the entire WordPress installation. The vulnerability is particularly concerning because it operates under the assumption that client-side validation is sufficient for security purposes, which is a common but dangerous misconception in web application development.
The operational impact of this vulnerability extends beyond simple cross-site scripting attacks, as it allows high-privilege users to bypass security restrictions that should normally protect against malicious code execution. Even when the unfiltered_html capability is properly disabled, which is a standard security practice for preventing unrestricted content injection, the vulnerability permits administrators to perform cross-site scripting attacks through the plugin's configuration interface. This represents a significant escalation of privileges and potential attack surface expansion, as the vulnerability can be exploited by users who already possess administrative access to manipulate the WordPress core functionality. The attack vector leverages the trust placed in the plugin's configuration interface while exploiting the absence of server-side validation to execute malicious payloads.
Security mitigation strategies for this vulnerability must address both the immediate code-level fixes and broader architectural improvements. The plugin developers should implement comprehensive server-side sanitization of all user inputs, including the WordPress Target Version parameter, using appropriate escaping functions and input validation routines. The solution must ensure that all submitted version strings are properly validated against acceptable patterns and sanitized before being processed or stored. Organizations should also consider implementing additional security monitoring for unusual configuration changes and maintain strict access control measures to limit administrative privileges. This vulnerability aligns with ATT&CK technique T1059.007 for script injection and T1548.001 for abuse of privileges, emphasizing the need for layered security approaches. The incident underscores the critical importance of server-side validation and the dangers of relying solely on client-side security measures, particularly in administrative interfaces where elevated privileges can be leveraged for more severe attacks.