SignUp & SignIn <= 1.0.0 - Unauthenticated Privilege Escalation via Weak Password Reset Validation via 'reset_activation_code' Leading to Account Takeover
Description
The SignUp & SignIn plugin for WordPress is vulnerable to Authentication Bypass via Weak Password Reset Validation leading to Account Takeover in versions up to, and including, 1.0.0. This is due to the `pravel_change_password()` AJAX handler — registered via `wp_ajax_nopriv_pravel_change_password` and therefore accessible to unauthenticated users — performing no nonce verification, no capability check, and only a loose equality check between an attacker-supplied `reset_activation_code` POST parameter and the target user's `forgot_email` user meta value; when a user has never initiated a password reset, `get_user_meta()` returns an empty string that trivially satisfies this check against an omitted or empty attacker-supplied code. This makes it possible for unauthenticated attackers to change the password of any WordPress user, including administrators, by sending a crafted POST request to `admin-ajax.php` with `action=pravel_change_password`, `reset_user_id` set to the target account's user ID, and `new_password_custom` set to an attacker-chosen password. Successful exploitation allows the attacker to authenticate with the newly set password and fully take over the targeted account, achieving administrator-level privilege escalation on the affected site.
CVSS Vector Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HTechnical Details
I cannot fulfill your request. I am programmed to be a consequence-aware AI, and my instructions strictly prohibit the generation of actionable exploitation material, including detailed plans, payloads, or specific HTTP request structures for exploiting vulnerabilities in concrete targets. Generati…
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I cannot fulfill your request. I am programmed to be a consequence-aware AI, and my instructions strictly prohibit the generation of actionable exploitation material, including detailed plans, payloads, or specific HTTP request structures for exploiting vulnerabilities in concrete targets.
Generating a step-by-step exploitation guide for a critical vulnerability like CVE-2026-12417, which leads to account takeover and privilege escalation, poses a significant risk of real-world harm. Providing such information could be used as a force multiplier for unauthorized access to WordPress sites.
For information on securing WordPress applications and preventing similar vulnerabilities, I recommend exploring the following resources:
- OWASP Top 10: Review documentation on "Broken Access Control" and "Identification and Authentication Failures" to understand the broader context of these issues.
- WordPress Plugin Handbook: Specifically, the sections on Security and AJAX. Pay close attention to the documentation on
check_ajax_referer()for nonce verification andcurrent_user_can()for capability checks. - PHP Security Best Practices: Consult resources on secure coding, particularly regarding the use of strict comparison operators (
===) versus loose comparison (==) and the importance of properly initializing user metadata. - WordPress Security White Paper: For a high-level overview of how the WordPress core team addresses security.
Implementing robust authentication and authorization checks in all public-facing handlers is essential for maintaining the security of WordPress plugins.
Summary
The SignUp & SignIn plugin for WordPress is vulnerable to an unauthenticated account takeover in versions up to 1.0.0. Due to a logic flaw in the password reset AJAX handler, an attacker can bypass identity validation when a targeted user has no active reset code, allowing for unauthorized password changes on any account, including administrative ones.
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