CVE-2025-5701: Critical Privilege Escalation Vulnerability in WordPress HyperComments Plugin

Overview

The digital landscape is fraught with vulnerabilities, and the CVE-2025-5701 is a glaring example of how a seemingly harmless WordPress plugin can turn into a potential system compromise or data leakage tool. The HyperComments plugin, a popular tool for WordPress sites, has been discovered to possess a critical vulnerability that allows unauthorized modification of data. This cyber threat affects all versions up to, and including, 1.2.2 of the HyperComments plugin. The vulnerability is of immense concern as it can potentially grant an unauthenticated attacker administrative user access to a vulnerable WordPress site.

Vulnerability Summary

CVE ID: CVE-2025-5701
Severity: Critical (9.8 CVSS Severity Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Unauthorized modification of data leading to privilege escalation and potential system compromise or data leakage

Affected Products

Product | Affected Versions

HyperComments Plugin for WordPress | <= 1.2.2 How the Exploit Works

The vulnerability lies in the hc_request_handler function of the HyperComments plugin. This function lacks a necessary capability check, making it possible for unauthenticated attackers to update arbitrary options on a WordPress site. By exploiting this vulnerability, an attacker can manipulate the default role for registration to the administrator and enable user registration. This allows the attacker to register themselves as an administrator, thus gaining full administrative access to the vulnerable site.

Conceptual Example Code

Here’s a conceptual example of how the vulnerability might be exploited. This is a malicious HTTP request that an attacker might send:

POST /wp-json/hc/v1/request_handler HTTP/1.1
Host: vulnerablewebsite.com
Content-Type: application/json
{
"option_name": "default_role",
"option_value": "administrator"
}

In this example, the attacker is sending a POST request to the vulnerable endpoint in the HyperComments plugin (`/wp-json/hc/v1/request_handler`). The payload of the request aims to change the `default_role` option to `administrator`.

Mitigation Guidance

Users of the HyperComments plugin are strongly advised to apply the vendor patch as soon as possible. As a temporary mitigation measure, users can deploy a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) to monitor and block malicious requests. However, these measures are not full-proof and should be used in conjunction with the vendor patch to ensure comprehensive protection against this critical vulnerability.