Attack Vectors

Medium severity (CVSS 6.5) vulnerability CVE-2025-13587 affects the WordPress plugin Two Factor (2FA) Authentication via Email (slug: two-factor-2fa-via-email) in versions up to and including 1.9.8.

The issue can be exploited during the login process because the plugin’s two-factor requirement is only enforced when a specific login parameter is missing. An attacker with valid username/password credentials (for example, obtained through password reuse, phishing, or prior credential exposure) could attempt to log in while supplying any value (even an empty one) in the token parameter, potentially bypassing the intended second factor.

This is especially relevant for organizations that rely on this plugin as a primary control to protect privileged accounts, remote access, or shared administrative logins.

Security Weakness

The weakness is a two-factor authentication bypass in the plugin’s login enforcement logic. Specifically, the plugin’s SS88_2FAVE::wp_login() method only enforces 2FA when the token HTTP GET parameter is undefined, which means that simply providing the parameter can prevent the 2FA check from being applied.

In practical business terms, this turns a “something you know + something you have” control into “something you know” in certain conditions—reducing the protective value of 2FA for accounts using this plugin.

Remediation: update Two Factor (2FA) Authentication via Email to version 1.9.9 or newer, as recommended by the source advisory.

Source: Wordfence vulnerability record.

Technical or Business Impacts

If exploited, this vulnerability can enable account takeover scenarios where the attacker already has a password but would normally be stopped by email-based 2FA. For marketing leaders and executives, the risk is less about the plugin itself and more about what an authenticated user can do once inside: change content, alter tracking scripts, redirect traffic, or access customer and campaign data depending on account permissions.

Potential business impacts include brand damage (malicious site changes or defacement), revenue loss (traffic redirection, disrupted lead capture), data governance concerns (unauthorized access to dashboards or customer information stored in WordPress), and compliance exposure if compromised accounts are used to access regulated data or to distribute malicious content through trusted channels.

Similar Attacks: Two-factor bypass and authentication logic flaws have been used in real-world incidents to enable unauthorized access. Examples include the 2022 Uber breach (credential-based access with MFA fatigue/social engineering), the 2023 LastPass incident updates (credential and access chain impacts), and ongoing credential-based intrusions tracked by CISA where weak or bypassed authentication controls contribute to compromise (CISA Cyber Threats & Advisories).

To reduce business risk quickly: patch to 1.9.9+, review admin/editor accounts for unusual logins and changes, and ensure privileged accounts use strong, unique passwords alongside a reliably enforced MFA method.