CVE-2026-3903
CSRF Vulnerability in Modular DS WordPress Plugin Allows OAuth Disconnection
Publication date: 2026-03-11
Last updated on: 2026-03-11
Assigner: Wordfence
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| modular_ds | monitor_update_and_backup_multiple_websites_plugin | to 2.5.1 (inc) |
| modular_connector | wordpress_plugin | to 2.6.0 (exc) |
| modular_connector | wordpress_plugin | 2.6.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-352 | The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
The vulnerability in the Modular DS: Monitor, update, and backup multiple websites plugin for WordPress is a Cross-Site Request Forgery (CSRF) issue affecting all versions up to and including 2.5.1. It occurs because the plugin's postConfirmOauth() function lacks nonce validation, which is a security measure to verify the authenticity of requests.
This flaw allows unauthenticated attackers to trick a site administrator into performing an action, such as clicking a malicious link, which can disconnect the plugin's OAuth/SSO connection without the administrator's consent.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing attackers to forcibly disconnect the OAuth/SSO connection of the plugin on your WordPress site without your authorization.
Such unauthorized disconnection could disrupt authentication flows, potentially causing denial of service for legitimate users relying on OAuth/SSO for access.
Since the vulnerability requires tricking an administrator into clicking a link, it also poses a social engineering risk.
The CVSS score of 4.3 (medium severity) reflects that the impact is limited to integrity (I:L) with no confidentiality or availability loss.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
Detection of this vulnerability involves monitoring for unauthorized or forged requests that attempt to disconnect the plugin's OAuth/SSO connection by exploiting missing nonce validation in the postConfirmOauth() function.
Since the vulnerability is related to Cross-Site Request Forgery (CSRF) attacks targeting the Modular DS WordPress plugin, detection can focus on identifying suspicious HTTP requests that lack proper authentication tokens or nonces.
You can check your web server logs for unusual POST requests to endpoints related to the plugin's OAuth/SSO functionality, especially those that might trigger the postConfirmOauth() function.
- Use command-line tools like grep to search for suspicious POST requests in your web server logs, for example: `grep -i 'postConfirmOauth' /var/log/apache2/access.log`
- Monitor for requests missing valid nonce parameters or with unexpected referrers that could indicate CSRF attempts.
- If you have access to the WordPress debug or plugin logs, review them for authentication failures or unexpected disconnection events.
What immediate steps should I take to mitigate this vulnerability?
The primary immediate mitigation step is to update the Modular DS: Monitor, update, and backup multiple websites plugin for WordPress to a version later than 2.5.1, where the vulnerability is fixed.
Since the vulnerability is due to missing nonce validation allowing CSRF attacks, applying the official patch or upgrading to a version that includes nonce validation and proper authentication checks will prevent exploitation.
Additionally, you should consider implementing general CSRF protections such as ensuring that all sensitive actions require valid nonces and that users are educated not to click on suspicious links.
If immediate update is not possible, restricting access to the plugin's OAuth/SSO endpoints via firewall rules or IP whitelisting can reduce exposure.