CVE-2026-101160 in Ultimate Review Plugin
Summary
by MITRE • 10/03/2026
The WP Ultimate Review WordPress plugin before 2.4.4 does not validate that a submitted review rating is numeric before storing it and later using it in numeric operations when rendering reviews, allowing unauthenticated users to make the reviewed content fail with a fatal error for all visitors until the review is removed (a persistent denial of service), when user reviews are enabled.
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Analysis
by VulDB Data Team • 10/03/2026
The vulnerability identified in WP Ultimate Review versions prior to 2.4.4 represents a critical input validation failure that leads to a persistent denial of service condition within WordPress environments utilizing this specific plugin. The core technical flaw lies in the application's handling of user-submitted review ratings, where the system fails to enforce strict type checking on incoming data fields designated for numerical values. When an unauthenticated visitor submits a rating through the public-facing interface, the backend processing logic accepts arbitrary string inputs without verifying that they conform to expected numeric formats before persisting them to the database. This lack of sanitization allows malicious actors to inject non-numeric characters or malformed strings directly into the review metadata stored in the WordPress database tables associated with the plugin.
The operational impact of this vulnerability is severe due to its persistent nature and broad reach. Once a maliciously crafted, non-numeric rating is saved by an attacker, it becomes part of the permanent dataset for that specific piece of content. The severity escalates when the system attempts to render reviews on the frontend or perform backend calculations involving these ratings. Because the application assumes all stored review data will be numeric during subsequent rendering operations and mathematical computations, encountering a non-numeric value triggers an unhandled exception in the PHP execution environment. This results in a fatal error that crashes the page load for any visitor attempting to view the affected content. Consequently, this transforms what might otherwise be a minor input validation issue into a significant availability risk, effectively taking down specific pages or posts indefinitely until the corrupted data is manually purged from the database by an administrator.
From a threat modeling perspective, this vulnerability aligns with CWE-20 Improper Input Validation and specifically relates to CWE-754: Improper Check for Unusual or Exceptional Conditions in code that handles numeric operations without verifying input types first. The attack vector is classified as unauthenticated access, meaning no credentials are required to exploit the flaw, which significantly lowers the barrier to entry for attackers seeking to disrupt service availability. In terms of the MITRE ATT&CK framework, this behavior corresponds to T1496: Resource Hijacking or more accurately in this context, a form of Denial of Service via application logic abuse where the attacker manipulates data integrity to cause system instability. The persistence of the error means that even after the initial attack is detected and stopped, the damage remains until remediation occurs, extending the window of impact beyond the active exploitation phase.
Mitigation strategies must focus on both immediate patching and long-term defensive coding practices. Administrators running affected versions should immediately upgrade to version 2.4.4 or later where this validation logic has been corrected. For environments that cannot be patched instantly due to compatibility constraints, a temporary workaround involves implementing server-side input filtering via web application firewall rules to reject requests containing non-numeric characters in the review rating parameters. Additionally, developers and administrators should audit existing reviews for potential corruption by querying the database for any entries where the rating field contains alphabetic or special characters rather than pure integers or decimals. Implementing strict type casting at the point of data ingestion and utilizing prepared statements with explicit type binding can prevent similar vulnerabilities in future development cycles, ensuring that numeric operations are only ever performed on validated numerical inputs.