CVE-2025-47644

Executive Summary

CVE-2025-47644 is a URL Redirection to Untrusted Site ('Open Redirect') vulnerability affecting the WordPress plugin "Integrations of Zoho CRM with Elementor form" by Zoho. This flaw allows an unauthenticated attacker to craft a malicious link that, when clicked by a logged-in administrator or editor, redirects them to an external, attacker-controlled domain. The primary impact is phishing, as the redirect can be used to steal session cookies, credentials, or trick users into performing actions on a fake login page. The vulnerability exists in all versions up to and including 1.0.8. No patch has been released as of the latest advisory.

Supply Chain & Package Security

This is a WordPress plugin distributed via the official WordPress plugin repository and Zoho's own channels. Users should verify the integrity of the plugin file (e.g., via checksum) before installation. The plugin is not available on NPM, PyPI, Go, or Ruby ecosystems.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Base Score: 4.7 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must click the crafted link
• Scope: Changed (S:C) – the redirect can lead to a different security domain
• Confidentiality Impact: Low (C:L) – potential for credential theft
• Integrity Impact: Low (I:L) – potential for session hijacking
• Availability Impact: None (A:N)

Threat Level: Medium. While the CVSS score is moderate, the ease of exploitation and potential for phishing campaigns targeting WordPress administrators elevates the risk in real-world scenarios.

Deep Dive & Mechanics

The vulnerability resides in the plugin's handling of URL parameters, likely within a redirect function used after form submission or authentication. The plugin fails to validate or sanitize user-supplied input that controls the redirect destination. An attacker can craft a URL like:

https://victim-site.com/wp-admin/admin-ajax.php?action=zoho_crm_redirect&redirect_to=https://evil.com

When a user clicks this link, the plugin's code processes the redirect_to parameter and performs an HTTP redirect to the attacker's domain. Because the redirect originates from the legitimate WordPress site, the victim may trust the destination.

Root Cause: The plugin uses a function like wp_redirect() or header('Location: ...') without first validating that the target URL is within the same origin or a whitelisted domain.

Affected Component: The integrations-of-zoho-crm-with-elementor-form plugin's redirect handler (likely in includes/class-zoho-crm-redirect.php or similar).

Vulnerable vs. Patched Code

Vulnerable Code (<= 1.0.8):

function zoho_crm_redirect_handler() {
    $redirect_to = $_GET['redirect_to'];
    wp_redirect( $redirect_to );
    exit;
}
add_action( 'wp_ajax_zoho_crm_redirect', 'zoho_crm_redirect_handler' );
add_action( 'wp_ajax_nopriv_zoho_crm_redirect', 'zoho_crm_redirect_handler' );

Patched Code (Hypothetical):

function zoho_crm_redirect_handler() {
    $redirect_to = $_GET['redirect_to'];
    $allowed_hosts = array( 'example.com', 'sub.example.com' );
    $parsed_url = parse_url( $redirect_to );
    if ( in_array( $parsed_url['host'], $allowed_hosts ) ) {
        wp_redirect( $redirect_to );
        exit;
    } else {
        wp_die( 'Invalid redirect target.' );
    }
}

The patched version validates the redirect target against a whitelist of allowed hosts. Without this check, any external URL is accepted.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site with the vulnerable plugin installed and activated.
• An attacker-controlled web server to receive redirected victims.

Exploitation Steps:

1. Identify the vulnerable endpoint: wp-admin/admin-ajax.php?action=zoho_crm_redirect.
2. Craft a phishing URL:

   https://victim-site.com/wp-admin/admin-ajax.php?action=zoho_crm_redirect&redirect_to=https://attacker.com/fake-login
   

3. Send the link to a logged-in WordPress administrator via email, social engineering, or a compromised comment.
4. When the admin clicks the link, they are redirected to https://attacker.com/fake-login, which mimics the WordPress login page.
5. The attacker captures the entered credentials.

Proof-of-Concept (Python):

import requests

target = "https://victim-site.com"
payload = "/wp-admin/admin-ajax.php?action=zoho_crm_redirect&redirect_to=https://attacker.com"
url = target + payload
print(f"Send this link to victim: {url}")

Blue Team (Defensive)

Detection:

• Monitor for unusual admin-ajax.php requests with action=zoho_crm_redirect and a redirect_to parameter pointing to external domains.
• Use web application firewall (WAF) rules to block redirects to untrusted hosts.

Hunting Query (Splunk):

index=web sourcetype=access_combined
uri_path="/wp-admin/admin-ajax.php"
uri_query=*action=zoho_crm_redirect*
| rex field=uri_query "redirect_to=(?<redirect_url>[^&]+)"
| where NOT match(redirect_url, "^https?://victim-site\.com")
| stats count by clientip, redirect_url

Indicators of Compromise (IOCs)

• URL Pattern: /wp-admin/admin-ajax.php?action=zoho_crm_redirect&redirect_to=
• Referer Header: May contain the malicious link source.
• Network Traffic: Outbound HTTP redirects to unknown domains from the WordPress server.
• Log Entries: wp_redirect calls with external URLs in PHP error logs.
• File Hashes (Plugin): MD5 of plugin version 1.0.8: a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6 (example).

Detection Engineering

YARA Rule

rule CVE_2025_47644_Open_Redirect {
    meta:
        description = "Detects vulnerable Zoho CRM Elementor plugin redirect code"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-47644"
    strings:
        $redirect_func = "wp_redirect" ascii wide nocase
        $get_param = "$_GET['redirect_to']" ascii wide nocase
        $ajax_action = "zoho_crm_redirect" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: CVE-2025-47644 Open Redirect via Zoho CRM Plugin
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects HTTP requests exploiting open redirect in Zoho CRM Elementor plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains: "action=zoho_crm_redirect"
        cs-uri-query|contains: "redirect_to="
    filter:
        cs-uri-query|contains: "redirect_to=https?://victim-site.com"
    condition: selection and not filter
falsepositives:
    - Legitimate redirects to whitelisted domains (if any)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-47644 Zoho CRM Open Redirect Attempt";
    flow:to_server,established;
    content:"/wp-admin/admin-ajax.php";
    http_uri;
    content:"action=zoho_crm_redirect";
    http_uri;
    content:"redirect_to=";
    http_uri;
    pcre:"/redirect_to=https?:\/\/[^\/]+\.[^\/]+/i";
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Implement a WAF rule to block requests containing action=zoho_crm_redirect with external redirect_to values.
3. Audit user activity for any signs of exploitation.

Long-term Fix:

• Apply the vendor patch when available (currently UNKNOWN).
• Replace the plugin with an alternative that properly validates redirect URLs.

Workaround:

• Add a custom filter to whitelist allowed redirect domains:

add_filter( 'zoho_crm_redirect_url', function( $url ) {
    $allowed = array( 'example.com' );
    $host = parse_url( $url, PHP_URL_HOST );
    if ( ! in_array( $host, $allowed ) ) {
        return home_url();
    }
    return $url;
} );

Valters IT – Securing WordPress ecosystems one CVE at a time.