CVE-2024-9756 is a vulnerability identified in the Order Attachments for WooCommerce plugin for WordPress, specifically affecting versions 2.0 through 2.4.1. The root cause is a missing authorization check (CWE-862) on the AJAX action wcoa_add_attachment, which handles file uploads attached to WooCommerce orders. This flaw allows any authenticated user with subscriber-level privileges or higher to upload files of limited types to the server without proper capability verification. Since subscriber-level users are typically low-privileged, this expands the attack surface beyond administrators or shop managers. The vulnerability does not require user interaction beyond authentication and can be exploited remotely over the network (AV:N). The CVSS 3.1 vector indicates low attack complexity (AC:L), privileges required (PR:L), no user interaction (UI:N), and impacts integrity only (I:L) without affecting confidentiality or availability. Although the plugin restricts file types, unauthorized uploads could be leveraged for further attacks such as web shell deployment or malicious content hosting if combined with other vulnerabilities or misconfigurations. No public exploits or active exploitation have been reported as of the publication date. The vulnerability was reserved and published in early October 2024, with no official patches linked yet, indicating a need for prompt vendor response or interim mitigations.

The primary impact of CVE-2024-9756 is on data integrity, as unauthorized file uploads can allow attackers to place malicious files on the server. While the plugin limits file types, attackers might still upload files that could be used for phishing, defacement, or as a foothold for further compromise if other vulnerabilities exist. This could lead to reputational damage, potential data manipulation, or indirect compromise of the e-commerce platform. Since the vulnerability requires authenticated access at subscriber level or above, the risk is somewhat mitigated by the need for user credentials, but subscriber accounts are often easier to obtain or create. The vulnerability does not directly affect confidentiality or availability, and no denial of service or data leakage is indicated. However, the presence of unauthorized files could complicate incident response and recovery. Organizations relying on WooCommerce with this plugin installed may face increased risk of targeted attacks, especially if they have weak user account controls or lack monitoring for unusual file uploads.

To mitigate CVE-2024-9756, organizations should first check for and apply any official patches or updates released by the plugin vendor once available. Until patches are released, administrators should restrict user roles to the minimum necessary, avoiding granting subscriber or higher privileges to untrusted users. Implement strict file upload monitoring and scanning to detect unauthorized or suspicious files uploaded via the plugin. Consider disabling or restricting the Order Attachments feature if not essential. Employ web application firewalls (WAFs) with custom rules to block unauthorized AJAX requests targeting wcoa_add_attachment. Regularly audit user accounts and permissions to prevent privilege escalation or unauthorized access. Additionally, harden the WordPress environment by disabling execution of uploaded files in upload directories and enforcing strong authentication mechanisms such as MFA. Monitoring logs for unusual activity related to file uploads can help detect exploitation attempts early.