OceanWP is a widely adopted WordPress theme, boasting over 50,000 active installations thanks to its performance-optimized code and extensive customization options. To further extend its capabilities, it relies on a companion plugin, Ocean Extra, which adds demo import, custom widgets, and additional theme settings. However, a critical vulnerability—CVE-2025-8891—has been discovered: an unauthenticated Cross-Site Request Forgery (CSRF) flaw that allows any visitor to invoke the oceanwp_notice_button_click AJAX action. This function, when called, automatically installs or activates the Ocean Extra plugin, effectively granting low-privileged users the ability to install new code on the site without any consent or proper authorization checks.
| CVE | CVE-2025-8891 |
| Plugin Version | OceanWP <= 4.0.9 |
| Critical | High |
| All Time | 22 883 377 |
| Active installations | 500 000+ |
| Publicly Published | May 30, 2025 |
| Last Updated | May 30, 2025 |
| Researcher | Dmitrii Ignatyev |
| PoC | Yes |
| Exploit | No |
| Reference | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-8891 https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-themes/oceanwp/oceanwp-411-cross-site-request-forgery-to-ocean-extra-plugin-installation |
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Timeline
| August 6, 2025 | Plugin testing and vulnerability detection in the OceanWP have been completed |
| August 6, 2025 | I contacted the author of the plugin and provided a vulnerability PoC with a description and recommendations for fixing |
| August 16, 2025 | Registered CVE-2025-8891 |
Discovery of the Vulnerability
During a security audit of the OceanWP theme, researchers identified that the AJAX action oceanwp_notice_button_click is registered via admin-ajax.php without nonce verification or capability checks. This action is intended to handle the user clicking on a notice prompting them to install Ocean Extra. Unfortunately, the theme’s developer localized the necessary script globally, exposing the action endpoint to all visitors. Consequently, when the action is triggered—typically by a button click in the admin UI—it performs the plugin installation or activation routine. Because no CSRF protections or user capabilities are enforced, attackers can silently trigger this functionality, installing Ocean Extra at will.
Understanding of Missing Authorization attack’s
WordPress best practices dictate that any AJAX endpoint altering server state must implement both nonce validation (to prevent CSRF) and capability checks (to ensure the user is authorized). In numerous past incidents—such as in the Twenty Twenty-One theme and other plugin/theme bundles—developers forgot one or both checks, leading to critical CSRF flaws. Attackers leveraged these weaknesses to install unapproved plugins, change site settings, or execute arbitrary code. In the case of OceanWP, the missing authorization on oceanwp_notice_button_click follows this pattern, enabling unauthorized plugin installation.
Exploiting the Missing Authorization Vulnerability
To exploit CVE-2025-8891, an attacker without any Cookies:
POC:
<html> <body> <form action="http://127.0.0.1/wordpress/wp-admin/admin-ajax.php" method="POST"> <input type="hidden" name="action" value="oceanwp_notice_button_click" /> <input type="submit" value="Submit request" /> </form> <script> history.pushState('', '', '/'); document.forms[0].submit(); </script> </body> </html>____
The ability to install a plugin without administrator intervention poses severe risks. Once Ocean Extra is installed, it could be leveraged to deploy further malicious code, inject backdoors, or modify site configuration to weaken security. In real-world scenarios, attackers could chain this exploit with vulnerabilities in Ocean Extra itself, achieve persistence, and execute arbitrary PHP code. E-commerce sites using OceanWP risk fraudulent charges, theft of customer data, or site downtime. Corporate or membership platforms may suffer from unauthorized data exfiltration or defacement. The exploit underscores how a single missing authorization check can cascade into full site compromise.
Recommendations for Improved Security
Enforce Nonce Verification: Update the theme to include check_ajax_referer( 'oceanwp_demo_import', 'security' ) or similar nonce checks before executing oceanwp_notice_button_click.
Add Capability Checks: Wrap the callback in a current_user_can( 'install_plugins' ) check to ensure only authorized administrators can trigger plugin installs.
Limit Script Localizations: Localize sensitive AJAX endpoints only in admin contexts and load scripts conditionally based on user capabilities.
Audit All AJAX Actions: Perform a full audit of add_action( 'wp_ajax_*' ) hooks to ensure nonces and capability verifications are uniformly enforced.
Educate Developers: Provide training on WordPress security best practices, emphasizing the dual requirement of CSRF and capability checks for all state-changing operations.
By taking proactive measures to address CSRF vulnerabilities like CVE-2025-8891 WordPress website owners can enhance their security posture and safeguard against potential exploitation. Stay vigilant, stay secure.
#WordPressSecurity #MissingAuthorization #WebsiteSafety #StayProtected #HighVulnerability
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Dmitrii I.