CVE-2025-68500

Executive Summary

CVE-2025-68500 is a Server-Side Request Forgery (SSRF) vulnerability discovered in the Prime Slider – Addons For Elementor WordPress plugin (slug: bdthemes-prime-slider-lite), developed by Bdthemes. The vulnerability affects all versions up to and including 4.0.10. This flaw allows an authenticated attacker with low privileges (e.g., subscriber or contributor) to make the vulnerable WordPress server send crafted HTTP requests to internal or external resources, potentially leading to information disclosure, internal network scanning, or further exploitation of internal services.

As this is a WordPress plugin vulnerability, the attack surface is limited to sites running the vulnerable plugin. The plugin is part of the Elementor ecosystem, a popular page builder for WordPress. The SSRF occurs due to insufficient validation of user-supplied URLs in the plugin's slider functionality, allowing the server to fetch arbitrary resources.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress Plugin Directory. The plugin is not an NPM, PyPI, Go, or Ruby package. However, the supply chain risk is significant: if the plugin is compromised or the vulnerability is exploited, it can lead to lateral movement within the hosting environment. Administrators should verify the integrity of the plugin files and ensure they are obtained from the official WordPress repository.

CVSS Breakdown & Threat Level

CVSS Score: 4.9 (Medium) Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

• Attack Vector (AV): Network – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low – No special conditions or race conditions are required.
• Privileges Required (PR): Low – An attacker needs a valid WordPress user account (e.g., subscriber).
• User Interaction (UI): None – No user action is required for exploitation.
• Scope (S): Unchanged – The vulnerable component and the affected resource are in the same security authority.
• Confidentiality (C): Low – Limited information disclosure (e.g., internal service banners, file contents).
• Integrity (I): Low – Limited ability to modify internal resources (e.g., writing to internal services).
• Availability (A): None – No impact on availability.

Threat Level: Medium. While the CVSS score is moderate, the SSRF can be chained with other vulnerabilities (e.g., internal service exploitation) to increase impact. The low EPSS score (0.0%) suggests limited active exploitation in the wild, but the lack of a patch increases risk.

Deep Dive & Mechanics

The SSRF vulnerability resides in the Prime Slider plugin's functionality that fetches external resources (e.g., images, data feeds) for slider content. The plugin likely uses WordPress's wp_remote_get() or wp_safe_remote_get() functions, but fails to properly validate or sanitize the URL parameter provided by the user.

Root Cause: The plugin does not restrict the URL scheme (e.g., file://, gopher://, dict://) or the target IP address (e.g., loopback, private IP ranges). An attacker can supply a URL pointing to internal services (e.g., http://127.0.0.1/wp-admin/admin-ajax.php) or cloud metadata endpoints (e.g., http://169.254.169.254/latest/meta-data/).

Attack Flow:

1. Attacker logs in as a low-privileged user (e.g., subscriber).
2. Attacker crafts a request to the vulnerable endpoint (e.g., wp-admin/admin-ajax.php?action=prime_slider_fetch&url=http://169.254.169.254/latest/meta-data/).
3. The server processes the request and fetches the internal resource.
4. The response is returned to the attacker, revealing sensitive information.

WordPress Ecosystem Context: This vulnerability is specific to the WordPress plugin and does not affect Apache or Nginx directly. The attack is performed through WordPress's AJAX API, which is a common attack vector for plugin vulnerabilities.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin's main PHP file (e.g., prime-slider-lite.php or a helper file). The vulnerable code likely looks like:

// Vulnerable code (hypothetical)
function prime_slider_fetch_url($url) {
    $response = wp_remote_get($url); // No validation
    return wp_remote_retrieve_body($response);
}

A patched version would include URL validation:

// Patched code (hypothetical)
function prime_slider_fetch_url($url) {
    $allowed_hosts = array('example.com', 'cdn.example.com');
    $parsed_url = parse_url($url);
    if (!in_array($parsed_url['host'], $allowed_hosts)) {
        return new WP_Error('invalid_url', 'URL not allowed');
    }
    $response = wp_safe_remote_get($url); // Uses wp_safe_remote_get
    return wp_remote_retrieve_body($response);
}

Key Differences:

• Use of wp_safe_remote_get() instead of wp_remote_get() to block private IPs.
• Whitelist-based URL validation.
• Error handling for invalid URLs.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress instance with Prime Slider plugin version <= 4.0.10.
• A low-privileged user account (e.g., subscriber).

Exploitation Steps:

1. Identify the vulnerable AJAX action (e.g., prime_slider_fetch).
2. Craft a request to fetch internal resources:

   curl -X POST 'http://target.com/wp-admin/admin-ajax.php' \
   -d 'action=prime_slider_fetch&url=http://169.254.169.254/latest/meta-data/'
   

3. If successful, the response will contain the cloud metadata.
4. For internal network scanning, use:

   curl -X POST 'http://target.com/wp-admin/admin-ajax.php' \
   -d 'action=prime_slider_fetch&url=http://192.168.1.1:80/'
   

Note: No public exploit code is available for this CVE.

Blue Team (Defensive)

Detection:

• Monitor for AJAX requests to admin-ajax.php with suspicious url parameters (e.g., containing 169.254.169.254, 127.0.0.1, or private IP ranges).
• Log all outbound HTTP requests from the WordPress server and alert on connections to internal IPs.

Hunting:

• Search web server logs for action=prime_slider_fetch and examine the url parameter.
• Use the Sigma rule below to detect exploitation attempts.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Outbound HTTP requests to private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 127.0.0.0/8).
  • Requests to cloud metadata endpoints (169.254.169.254, 100.100.100.200 for Alibaba Cloud).
  • Requests to internal services (e.g., http://localhost:3306, http://127.0.0.1:80).

• File IOCs:

  • Modified plugin files in /wp-content/plugins/bdthemes-prime-slider-lite/.
  • Suspicious log entries in /var/log/apache2/access.log or /var/log/nginx/access.log.

• Behavioral IOCs:

  • Unusual outbound connections from the web server to internal IPs.
  • AJAX requests with action=prime_slider_fetch and non-standard URLs.

Detection Engineering

YARA Rule

rule CVE_2025_68500_SSRF_PrimeSlider {
    meta:
        description = "Detects SSRF exploitation attempts against CVE-2025-68500 in Prime Slider plugin"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-68500"
    strings:
        $ajax_action = "action=prime_slider_fetch"
        $url_param = "url="
        $internal_ip = /(127\.0\.0\.1|10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2\d|3[01])\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3})/
        $metadata_ip = "169.254.169.254"
    condition:
        $ajax_action and $url_param and ($internal_ip or $metadata_ip)
}

Sigma Rule

title: CVE-2025-68500 SSRF Exploitation via Prime Slider Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects SSRF attempts against CVE-2025-68500 in WordPress Prime Slider plugin
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=prime_slider_fetch'
        cs-uri-query|contains: 'url='
    filter:
        cs-uri-query|contains:
            - 'http://'
            - 'https://'
    condition: selection and not filter
falsepositives:
    - Legitimate use of the plugin to fetch external resources
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-68500 SSRF Exploitation - Prime Slider Plugin"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=prime_slider_fetch"; http_client_body; content:"url="; http_client_body; pcre:"/(127\.0\.0\.1|10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2\d|3[01])\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3}|169\.254\.169\.254)/Ri"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released by Bdthemes.
2. Restrict outbound HTTP requests from the WordPress server using firewall rules (e.g., block private IP ranges in iptables).
3. Implement a Web Application Firewall (WAF) rule to block requests containing action=prime_slider_fetch with suspicious URLs.

Long-term Fix:

• Apply the official patch from Bdthemes when available.
• Update the plugin to the latest version (if a patched version is released).
• Conduct a security audit of all WordPress plugins for similar SSRF vulnerabilities.

Workaround:

• Add the following code to the theme's functions.php to block the vulnerable AJAX action:

  add_action('wp_ajax_prime_slider_fetch', function() {
      wp_die('Action disabled for security reasons.');
  }, 1);
  add_action('wp_ajax_nopriv_prime_slider_fetch', function() {
      wp_die('Action disabled for security reasons.');
  }, 1);
  

Valters IT
Securing Digital Frontiers