Preventing Open Redirect Abuse in Donation Plugin | CVE202568602 | 2025-12-27

Plugin Name	WordPress Accept Donations with PayPal Plugin
Type of Vulnerability	Open Redirect
CVE Number	CVE-2025-68602
Urgency	Low
CVE Publish Date	2025-12-27
Source URL	CVE-2025-68602

Executive Summary

On December 27, 2025, a new vulnerability identified as CVE-2025-68602 was disclosed affecting the popular WordPress plugin Accept Donations with PayPal (versions ≤ 1.5.1). This vulnerability is categorized as an open redirection flaw. Simply put, the plugin incorrectly processes user-supplied URLs and redirects visitors to potentially malicious external domains without proper validation.

Attackers can exploit this flaw by crafting deceptive links that seem to originate from a trusted site but then redirect users to fraudulent sites designed for phishing, credential theft, or malware distribution. Although this vulnerability is assessed as low urgency (CVSS score 4.7) due to requiring user interaction, the risk to donor trust and website reputations handling payments or donations remains significant.

At Managed-WP, we emphasize rapid, expert response to plugin vulnerabilities. This article provides a detailed analysis of the vulnerability, recommended mitigation strategies, developer best practices, and how Managed-WP helps protect your WordPress environment now and in the future.

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Understanding the Open Redirection Vulnerability

An open redirection occurs when a web application accepts an untrusted input—often parameters like redirect, next, or return_url—and sends users to those URLs without validation. This flaw exposes users to social engineering risks, as attackers can embed links that initially appear to lead to legitimate sites but then redirect to malicious pages.

• Phishing campaigns leverage this to trick users into trusting malicious links associated with trusted domains.
• URL filters and reputation checks can be bypassed because the initial URL is legitimate.
• Attackers chain redirects to obscure final attack destinations.

In WordPress plugins, this typically arises when a “thank you” or donation confirmation page URL is accepted from user input without verifying its safety.

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The Vulnerability Details: Accept Donations with PayPal (≤ 1.5.1)

• Affected Plugin: Accept Donations with PayPal
• Versions Impacted: 1.5.1 and earlier
• Vulnerability Type: Open Redirection
• CVE Reference: CVE-2025-68602
• Privilege Needed: None (Exploitable without authentication)
• User Interaction: Required (Victim must click a malicious link)
• Disclosure Date: December 2025

The core issue lies in the plugin’s handling of redirect parameters such as redirect_to or return_url. These values are taken from HTTP GET or POST requests and used directly in PHP’s header("Location: ...") or WordPress’s wp_redirect() function without verifying the target destination.

This allows redirection to arbitrary external URLs, potentially endangering your users to external threats.

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Proof-of-Concept (PoC)

1. Example malicious link:
   https://example.org/wp-admin/admin.php?page=paypal-donate&return_url=https%3A%2F%2Fevil.example%2Flogin
2. Clicking the link causes the plugin to redirect the browser to:
   https://evil.example/login

Users believe they are interacting with your legitimate site but are instead redirected to attacker-controlled sites designed to steal credentials or install malware.

Important: Do not test this vulnerability on websites you do not own or without permission to avoid legal and ethical violations.

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Why This Vulnerability Matters Despite Its “Low” Severity

• This vulnerability does not grant remote code execution or direct data compromise, but it serves as a powerful tool for attackers to perpetrate phishing and social engineering.
• Leveraging the trust of your domain reputation increases attack effectiveness.
• Donation payment flows are sensitive, and compromised redirect links can damage your organization’s reputation and donor confidence.
• When combined with other vulnerabilities, the attack surface and impact escalate.
• High-traffic donation pages become attractive and potentially lucrative targets.

Business impact and potential customer trust erosion make mitigating this issue a priority.

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Who Should Be Concerned?

• WordPress sites running any version of “Accept Donations with PayPal” ≤ 1.5.1.
• Administrators who rely on the plugin’s donation and redirect functionality.
• Sites that expose redirect parameters to unauthenticated users.

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Immediate Steps for Site Owners & Admins

Follow these short-term actions to reduce your exposure — prioritized by ease and impact:

1. Verify Plugin Version
   • Check your WordPress dashboard under Plugins > Installed Plugins.
   • If version ≤ 1.5.1 is active, consider it vulnerable until remediated.
2. Deactivate Plugin if Possible
   • Temporarily disable if donation processing can be paused.
   • This eliminates the attack surface.
3. Configure WAF or Virtual Patch
   • Use Web Application Firewall rules to block redirect parameters containing external URLs.
   • Block requests where parameters like redirect_to start with http:// or https:// and the destination host is not trusted.
4. Add Server-side Redirect Validation
   • Deploy a simple must-use plugin to validate redirect parameters using wp_validate_redirect().
   • Example snippet provided below can be adapted to your site:

   // mu-plugins/redirect-validate.php
   add_action( 'init', function() {
       $params = ['return_url','redirect_to','next','back'];
       foreach ( $params as $p ) {
           if ( isset($_REQUEST[$p]) && ! empty( $_REQUEST[$p] ) ) {
               $target = wp_unslash( $_REQUEST[$p] );
               $safe = wp_validate_redirect( $target, home_url('/') );
               if ( $safe !== $target ) {
                   header('HTTP/1.1 400 Bad Request');
                   exit('Invalid redirect parameter.');
               }
           }
       }
   }, 1 );
   

5. Educate Your Team & Donors
   • Inform your mailing lists and social media followers about phishing risks.
   • Provide clear official donation links to avoid confusion.
6. Monitor Logs & Alerts
   • Track redirects in logs that point to external domains.
   • Keep vigilant to suspicious patterns involving donation URLs.
7. Update Plugin When Patch Is Released
   • Follow plugin developer announcements for security updates.
   • Install official fixes from trusted sources promptly.

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How Managed-WP Protects Your Site

Managed-WP offers comprehensive WordPress security solutions tailored to close gaps like this open redirect flaw:

• Managed WAF Rules — Custom rule sets are instantly updated and pushed to protect your site against emerging plugin vulnerabilities.
• Virtual Patching — Blocks exploit attempts at the firewall level without waiting for plugin author fixes.
• Malware Scanner — Regular automated scans detect phishing and injected redirect scripts.
• Monitoring & Alerts — Real-time monitoring notifies administrators of suspicious redirection activity.
• Redirect Whitelisting — Policies enforce restrictions on allowed redirect destinations to prevent outbound abuse.

Even the free Managed-WP Basic plan provides robust protection sufficient to mitigate this risk while you apply permanent fixes.

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Developer Best Practices for Secure Redirects

If you’re maintaining or consulting on the plugin, implement these secure coding strategies:

1. Reject Arbitrary Absolute URLs
   • Only allow relative, internal paths or validate hosts strictly.
2. Use WordPress Helper Functions
   • wp_validate_redirect($location, $default) — safely validates redirect URLs.
   • wp_safe_redirect($location, $status) — safely redirects to internal URLs.
   • Sanitize inputs using esc_url_raw() or sanitize_text_field().
3. Prefer Tokenized Redirects

   // Example: map tokens to internal paths
   $allowed_pages = [
       'donation_thanks' => '/donate/thank-you/',
       'profile'         => '/user/profile/',
   ];
   $key = isset($_GET['return_key']) ? sanitize_text_field($_GET['return_key']) : '';
   $redirect = isset($allowed_pages[$key]) ? $allowed_pages[$key] : home_url('/');
   wp_safe_redirect($redirect);
   exit;
   

4. Whitelist External Hosts If Absolute URLs Are Needed

   $allowed_hosts = ['example.org', 'payments.example.org'];
   $url = esc_url_raw($_GET['return_url'] ?? '');
   $parts = wp_parse_url($url);
   if (!empty($parts['host']) && in_array($parts['host'], $allowed_hosts, true)) {
       wp_safe_redirect($url);
       exit;
   } else {
       wp_safe_redirect(home_url('/'));
       exit;
   }
   

5. Implement Logging & Rate Limiting
   • Log unusual redirect parameters and limit abusive requests.
   • Notify admins about potential attacks.
6. Include Redirect Checks in Testing & Reviews
   • Unit tests and code reviews should focus on sanitization and redirect validation.

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ModSecurity WAF Rule Example

You can add the following ModSecurity rule as a temporary server-level protection:

# Block external redirect parameters
SecRule ARGS_NAMES "(?:return_url|redirect_to|next|back|url)$" 
    "id:1000011,phase:2,deny,log,msg:'Blocking external redirect parameter',chain"
SecRule ARGS "@rx ^https?://" "t:none"

Adapt parameter names and whitelist your domains carefully to minimize false positives.

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Detection and Incident Handling

If you suspect your site was exploited through this vulnerability, act immediately:

1. Analyze Logs for requests with external redirect parameters and suspicious referrers.
2. Inspect Your Site for phishing pages or unauthorized files.
3. Reset Credentials if you suspect credential theft.
4. Communicate With Users transparently about the incident and recommended actions.
5. Engage Security Experts or Managed-WP for incident response if needed.

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Practical Checks for Site Safety

• Search audit logs for redirect parameters containing external URLs.
• Run automated vulnerability scans including redirect checks.
• Review plugin code for redirect implementation in a safe staging environment.
• Audit custom forms or handlers that might use unvalidated redirect targets.

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Long-Term Prevention Best Practices

• Default to internal-only redirect destinations.
• Use token-based redirect keys with server-side mapping.
• Strictly whitelist external domains if needed.
• Include redirect validation in developer checklists and testing.
• Incorporate automated secure coding scans into your development pipeline.
• Design email campaigns to avoid raw redirect URLs in links.

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Special Considerations for Donation Workflows

Donation pages are inherently high-trust environments and attractive targets for attackers:

• Donors are prone to click donation links in emails or social media without suspicion.
• Fraudsters can impersonate donation confirmations to capture sensitive payment information.
• Security breaches here risk both financial loss and long-term trust damage.

Ensure your donation flow does not expose unsafe redirects and maintain strict controls around them.

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Concise Incident Response Playbook

1. Discovery: WAF alerts or reports indicating redirects to external domains.
2. Containment: Disable vulnerable plugin or enable redirect-blocking firewall rules; remove harmful pages.
3. Investigation: Analyze logs for access patterns and lateral movement.
4. Eradication: Remove malicious files, restore clean backups, rotate credentials.
5. Recovery: Apply patches or code fixes; re-enable services with heightened monitoring.
6. Lessons Learned: Strengthen redirect validation and monitoring.

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Common Questions

Q: Does redirecting only after donations reduce risk?
A: It reduces the scale of automated abuse but attackers can still use social engineering to target users with malicious links. Always treat donation redirects with caution.

Q: Can JavaScript filtering of redirects protect me?
A: Client-side filtering is easily bypassed. Server-side validation with WordPress functions like wp_validate_redirect() is essential.

Q: Are logged-in users more vulnerable?
A: This vulnerability is exploitable by unauthenticated attackers; logged-in users might be targeted with more convincing phishing links but are not inherently more vulnerable.

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Final Thoughts from Managed-WP Security Experts

Open redirect vulnerabilities, though technically less severe than code execution flaws, remain critical social engineering enablers that can severely damage your WordPress site’s reputation and expose your users to phishing and malware.

If you use the Accept Donations with PayPal plugin version 1.5.1 or older, act now:

• Disable the vulnerable plugin if possible.
• Implement firewall rules or virtual patches to block unsafe redirects.
• Apply server-side validation in your redirect flow.
• Consider subscribing to Managed-WP for ongoing detection, virtual patching, and incident response support.

Our Managed-WP team is ready to help secure your website quickly and effectively so you can focus on your mission without worrying about preventable attacks.

Stay safe,
Managed-WP Security Team

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