CVE-2024-8009 is a high-severity vulnerability (CVSS 7.5) affecting the Sensei LMS WordPress plugin versions prior to 4.20.0. The vulnerability is classified under CWE-863, indicating an Incorrect Authorization issue. Specifically, this flaw allows teachers who have access to the students page within the LMS to view a list of all users on the blog, including their email addresses, without proper authorization controls. This means that sensitive user information is exposed beyond intended access boundaries. The vulnerability does not require any privileges or user interaction to exploit (AV:N/AC:L/PR:N/UI:N), making it remotely exploitable by any unauthenticated user with access to the teachers page. The impact is primarily on availability (as per the CVSS vector), but the disclosure of email addresses can also lead to privacy violations and facilitate further attacks such as phishing or social engineering. No known exploits are currently reported in the wild, and no official patches are linked yet, indicating that organizations using affected versions remain vulnerable until an update is released. The vulnerability affects all versions before 4.20.0, and since Sensei LMS is a popular WordPress plugin for educational content management, many sites using it could be at risk. The issue arises from improper authorization checks that fail to restrict access to user data only to authorized personnel, violating the principle of least privilege and exposing sensitive user information to unauthorized roles within the LMS environment.

For European organizations, the exposure of user email addresses through this vulnerability can have significant privacy and compliance implications, especially under GDPR regulations which mandate strict controls over personal data. Educational institutions and corporate training providers using Sensei LMS could inadvertently disclose personal data of students and staff, risking regulatory fines and reputational damage. Beyond privacy concerns, attackers could leverage the exposed email addresses to conduct targeted phishing campaigns, credential stuffing, or social engineering attacks against users. This could lead to broader compromise of organizational systems if attackers gain access through these vectors. The vulnerability also undermines trust in the LMS platform, potentially disrupting educational operations. Since the vulnerability is remotely exploitable without authentication, it increases the attack surface and the likelihood of exploitation, particularly in environments where the teachers page is accessible over the internet or insufficiently protected by network controls.

European organizations should immediately audit their Sensei LMS plugin versions and upgrade to version 4.20.0 or later once available to ensure the authorization flaw is patched. Until a patch is released, organizations should restrict access to the teachers page by implementing network-level controls such as IP whitelisting or VPN-only access to the WordPress admin area. Additionally, applying strict role-based access controls within WordPress to limit teacher roles and permissions can reduce exposure. Monitoring web server logs for unusual access patterns to the students page can help detect potential exploitation attempts. Organizations should also educate teachers and administrators about phishing risks stemming from exposed email addresses. Finally, conducting a privacy impact assessment and notifying affected users in compliance with GDPR may be necessary if data disclosure has occurred.