Summary

A high-severity vulnerability affecting the IDonate WordPress plugin (versions 2.1.5 through 2.1.9) allows an authenticated low-privileged user (subscriber) to escalate privileges via improper authorization checks in the plugin’s donor password functionality (CVE-2025-4519). The issue is fixed in version 2.1.10.

If your site runs IDonate and has any authenticated users beyond anonymous visitors—particularly subscribers—assume risk and act immediately. This post explains the vulnerability, why it is dangerous, immediate actions, detection and recovery advice, and long-term hardening measures. It also describes how an application firewall and virtual patching can provide temporary protection while you test and deploy updates.

What happened (plain English)

The IDonate plugin provides a function for managing donor passwords. The implementation checked that requests came from authenticated users but failed to verify whether the authenticated user was authorised to change the targeted donor’s password. This missing authorization allows a malicious authenticated account (for example, a subscriber) to change the password for another donor account — including privileged accounts — enabling account takeover or privilege escalation.

Many WordPress sites have at least one low-privilege account (subscribers, supporters, donors). That makes this type of flaw attractive to attackers, who can escalate privileges, create backdoors, or take full control once they exploit it.

Affected versions and timeline

• Affected plugin: IDonate
• Vulnerable versions: 2.1.5 – 2.1.9
• Fixed in: 2.1.10
• CVE: CVE-2025-4519
• Reported: November 2025
• Impact: Privilege escalation / account takeover from authenticated low-privilege accounts

Why this is high severity

• Requires only a low-privileged authenticated account (Subscriber).
• Can lead to account takeover of admin or privileged donor accounts.
• Successful escalation allows attackers to install malware, create admin users, exfiltrate data, change content, or pivot to the hosting account.
• Automated scans and mass exploitation can find many sites with the vulnerable plugin and any registered subscriber account.

High-level technical explanation (safe, non-exploitative)

The vulnerable flow in summary:

1. The plugin exposes an endpoint or AJAX handler that accepts a donor ID and a new password.
2. The handler checks that the request comes from an authenticated user, but it does not verify that the authenticated user owns or is authorised to modify the specified donor account.
3. The handler updates the donor’s password in the database without ensuring the caller has permission to do so.

Correct practice requires enforcing capability checks such as current_user_can('edit_user', $donor_id) or verifying that the current user ID equals the donor ID for self-service changes. Whether the plugin updates WordPress core user passwords or maintains a separate donor table, ownership and capability checks are essential.

No exploit steps are provided here — the goal is to explain impact, detection, and mitigation.

Immediate actions you must take (ordered)

1. Upgrade to IDonate 2.1.10 immediately.
   The vendor released a fix in 2.1.10. Update the plugin on all affected sites as soon as you can in a maintenance window.
2. If you cannot update immediately — apply virtual patching or block the endpoint.
   Use available perimeter controls (application firewall or hosting controls) to block requests to the plugin endpoints that handle donor password updates until you can apply the vendor patch.
3. Force password resets for high-privilege users and audit accounts.
   Reset passwords (and expire sessions) for all administrators, editors, and donor accounts with elevated permissions. Remove any recently created or unknown admin users.
4. Audit logs for suspicious activity.
   Search web server and WordPress logs for unusual POST requests to plugin endpoints and for logins from unusual IPs. Look for sudden password changes or profile updates around the disclosure date.
5. Scan for indicators of compromise.
   Run a full site malware scan, search for modified files, new PHP files in uploads, suspicious scheduled tasks, and unusual outbound connections. If you find signs of compromise, follow incident response steps below.
6. Harden accounts and sessions.
   Enforce stronger passwords, implement two-factor authentication for privileged users, and consider restricting registrations or requiring approval for new users.
7. Back up before and after remediation.
   Make a full site and database backup before applying changes, then create another known-good backup after remediation.

Safe detection checklist

These signs are suspicious but not definitive proof of exploitation:

• POST requests to plugin endpoints mentioning “donor”, “password”, “idonate”, or similar around the disclosure date.
• Multiple password change requests targeting different user IDs from the same authenticated user.
• New admin users created shortly before or after suspicious password updates.
• Changes to critical files: wp-config.php, active theme files, plugin files, or unexpected PHP in uploads.
• Unexpected outbound connections from PHP processes (check host or firewall logs).
• Resets or lockouts where previously valid admin credentials no longer work.

Use centralized logs (server access logs, WordPress activity logs), database audit queries, and file integrity monitoring for investigation.

Recommended WAF / virtual patching rules (conceptual, safe)

If you cannot patch immediately, apply virtual patching rules at your perimeter. Below are conceptual, non-exploitative rules for your administrator to implement and test:

• Block or rate-limit POST requests to paths used by the plugin’s donor password functionality. Inspect patterns rather than applying blunt blocks so legitimate traffic is not disrupted.
• Block requests missing a valid WordPress nonce for account or password updates.
• Enforce same-origin checks and block obvious CSRF attempts to the donor password endpoint.
• Restrict password change requests to users that own the target account: if the plugin uses an id parameter, prevent authenticated users from changing other users’ passwords by ensuring the authenticated user’s ID matches the target ID; if that is not possible at the perimeter level, block the endpoint until patched.
• Rate-limit authenticated users to reduce automated exploitation attempts from a single low-privileged account.

Test rules in monitoring mode before full enforcement to avoid breaking normal site functions.

Incident response — if you suspect exploitation

1. Isolate the site: consider maintenance mode while investigating.
2. Preserve logs and backups: make offline copies for forensic review.
3. Reset credentials: force password resets for privileged accounts and rotate salts/keys in wp-config.php to invalidate active cookies and sessions.
4. Remove unknown admin users and suspicious code/files.
5. Restore from a known-good backup if the filesystem shows tampering and you cannot fully remove malicious artifacts.
6. Reinstall WordPress core, plugins, and themes from trusted sources.
7. Perform malware scans and host-side checks for persistent backdoors or root compromise.
8. Review webserver and hosting access logs for suspicious activity and credentials misuse.
9. Monitor for re-infection and engage professional incident response if compromise is extensive.

Long-term mitigations and hardening

• Minimise the number of privileged users; avoid using admin accounts for day-to-day tasks.
• Enable two-factor authentication for all administrators and elevated accounts.
• Use strict role management and limit capabilities to what’s necessary.
• Keep themes, plugins, and core up to date — establish a maintenance schedule.
• Use a perimeter control (WAF) to apply virtual patches where necessary, but always plan for vendor fixes.
• Harden logins: limit login attempts, force strong passwords, and protect or disable unused XML-RPC endpoints.
• Implement file integrity monitoring and regular malware scans.
• Maintain regular backups with offsite retention and automated restore testing.

How to audit your site for this specific issue (safe approach)

• Confirm plugin version: In WordPress admin → Plugins, check IDonate version. If between 2.1.5 and 2.1.9, treat the site as vulnerable.
• Inspect access logs: look for POSTs to the plugin’s endpoints or to admin-ajax.php with suspicious action names or parameters.
• Use activity logs: review recent user password updates or profile edits if an activity logger exists.
• Verify user list: look for unexpected users with elevated permissions; check registration and last-updated timestamps.
• Check recent database changes: search for unexpected updates in the users table or plugin tables using timestamps around the vulnerability window.

If no concerning signs appear, patch and continue monitoring. If you find suspicious actions, follow the incident response steps above.

Secure development takeaways for plugin authors (brief)

• Never assume authentication implies authorization — always check the current user’s rights on the resource.
• Use WordPress capability APIs such as current_user_can('edit_user', $user_id).
• For self-service actions, confirm the owner is performing the action or the caller has an admin capability.
• Protect state-changing requests with nonces and verify them server-side.
• Limit sensitive actions to POST requests and implement same-origin checks in addition to nonces and capability checks.
• Use core APIs and prepared statements for database writes to avoid injection and data corruption.
• Add automated tests for authorization logic (unit and integration tests).

Detection rules and sample logs (for ops teams) — what to look for

Safe, non-exploitative patterns to hunt for suspicious activity:

• Webserver access logs: POST requests to plugin script paths with parameters like donor_id, password, new_pass, or action=idonate_....
• admin-ajax.php activity: repeated POSTs with unknown actions coming from low-privilege user sessions.
• Multiple password changes from the same subscriber account targeting other user IDs.
• Sudden creation of an admin user shortly after suspicious POST requests.
• Unusual user agent strings combined with POST requests to plugin endpoints.

If you have SIEM, create alerts on these patterns and feed them into your incident response process.

Recovery checklist (concise)

• Upgrade plugin to 2.1.10.
• Reset privileged user passwords and invalidate sessions (rotate salts/keys).
• Review admin user list and remove unknown accounts.
• Scan for malicious files and suspicious cron jobs.
• Restore from a clean backup if necessary.
• Harden site settings and enable two-factor authentication.
• Enable monitoring and apply perimeter protections (virtual patching) until patching is complete.