CVE-2026-100157 in WP Ultimate Review Plugin
Summary
by MITRE • 10/03/2026
The The WP Ultimate Review plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 2.4.3. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes. The nonce required to pass the only gate is emitted to unauthenticated visitors via the public review form, and submitted shortcode payloads are auto-published without admin approval by default, meaning exploitation requires no account and no privileged interaction.
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Analysis
by VulDB Data Team • 10/03/2026
The WP Ultimate Review plugin for WordPress contains a critical security vulnerability affecting all versions up to and including 2.4.3 that allows unauthenticated attackers to execute arbitrary shortcodes within the context of the website. This flaw stems from an improper validation mechanism where user-supplied input is passed directly into the do_shortcode function without adequate sanitization or authorization checks. The core issue lies in the failure to restrict which specific shortcode tags can be processed, thereby granting any visitor with access to the public-facing interface the ability to inject and execute malicious code payloads that are interpreted by the WordPress engine as native plugin functions.
The operational impact of this vulnerability is severe due to the lack of authentication requirements for exploitation. The security gate typically provided by nonces in WordPress forms is effectively neutralized because the nonce required to submit a review or trigger an action is emitted publicly via the standard review form interface. This means that any visitor, regardless of their user role or login status, can obtain this token and use it to bypass access controls. Furthermore, the default configuration of the plugin auto-publishes submitted content without requiring administrative approval, which allows malicious shortcode payloads to take effect immediately upon submission rather than waiting for manual review by a site administrator.
From an architectural perspective, this vulnerability represents a classic case of insecure direct object reference combined with command injection through template processing mechanisms. The attacker can leverage known shortcodes registered by other plugins or core WordPress features to perform actions such as reading sensitive files, executing system commands if certain conditions are met, or manipulating database entries. This capability effectively breaks the isolation between unauthenticated users and privileged administrative functions, potentially leading to full site compromise depending on the specific shortcodes available in the environment.
This vulnerability aligns with CWE-94 Improper Control of Generation of Code (Code Injection) as it involves injecting executable code via user input that is then processed by a parser. Additionally, it maps to ATT&CK technique T1059 Command and Scripting Interpreter where attackers use built-in system tools or scripts to execute commands on the target host. The lack of authentication bypasses also relates to CWE-287 Improper Authentication, although in this specific context, the primary vector is the injection itself rather than just identity theft.
Mitigation strategies should prioritize immediate remediation by upgrading the WP Ultimate Review plugin to a version later than 2.4.3 where these validation issues have been addressed. In cases where an upgrade is not immediately feasible, administrators can implement temporary workarounds such as disabling shortcodes in user-generated content through custom code filters or restricting access to the review submission endpoints via server-level rules like .htaccess files until a patch is applied. Regular auditing of plugin configurations and ensuring that auto-publishing features are disabled for untrusted inputs can also reduce the risk surface associated with this type of vulnerability.