CVE-2021-24894

Reviews Plus < 1.2.14 - Denial of Service

2021-10-25 00:00
Drew Jones

Strategic Overview

Status
Patched in 1.2.15
Affected Plugin
Reviews Plus
Affected Version
< 1.2.14
CVSS
6.5Medium
Weakness type
CWE-400 · Uncontrolled Resource Consumption
CVE
CVE-2021-24894
View all Reviews Plus vulnerabilities

At a glance

CVE-2021-24894 is a medium-severity Uncontrolled Resource Consumption vulnerability in the Reviews Plus WordPress plugin, affecting versions < 1.2.14. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high availability impact). The issue is fixed in version 1.2.15; sites on affected versions should update now. Disclosed October 2021, reported by Drew Jones.

Vulnerability Overview

The Reviews Plus plugin for WordPress is vulnerable to Denial of Service in versions before 1.2.14. This is due to an unknown part of the file post/page of the component Rating Submission Handler. The manipulation with an unknown input leads to a denial of service vulnerability. This makes it possible for authentication attackers, a authentication is necessary for exploitation to cause a Denial of Service in the review section when an authenticated user submit such rating and the reviews are set to be displayed on the post/page.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on availability.

CWE-400: Uncontrolled Resource Consumption

Reaching this weakness in Reviews Plus < 1.2.14 takes a caller who can reach the endpoint. Uncontrolled resource consumption means a request can make the server do an amount of work it never bounds, because the size or repetition of the job is taken from the request rather than capped by the code.

A single caller can hold PHP workers, database connections or disk open long enough to slow the site for everyone, without needing any account or any other flaw. For Reviews Plus the fix is 1.2.15: builds < 1.2.14 are affected, anything from 1.2.15 onward is not.

Remediation

Update to version 1.2.15, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Reviews Plus: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Reviews Plus 1.2.15 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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