Cross-Site Scripting (XSS) via File Upload in Alf.io

The primary impact of CVE-2024-25627 stems from the ability of an attacker to inject and execute arbitrary JavaScript code within the Alf.io application. This can be achieved by exploiting the vulnerability to upload HTML files containing malicious scripts. Successful exploitation allows an attacker to steal user session cookies, potentially gaining unauthorized access to user accounts and performing actions on their behalf. Furthermore, the attacker could deface the application, redirect users to malicious websites, or inject further malicious content. The blast radius is limited to users interacting with the affected Alf.io instance, and the attacker requires administrative access to initiate the attack.

Organizations and individuals using Alf.io for event attendance management, particularly those running versions prior to 2.0-M4-2402, are at risk. This includes those with limited security expertise who may not be aware of the vulnerability or its potential impact. Shared hosting environments where multiple users share the same Alf.io instance are also at increased risk.

• linux / server: Examine Alf.io application logs for suspicious file uploads, particularly HTML files containing JavaScript code. Use grep to search for patterns like <script> or javascript: within the logs.

grep -r '<script' /var/log/alf.io/*

• generic web: Check Alf.io application's file upload functionality for lack of proper sanitization. Attempt to upload a simple HTML file containing a JavaScript alert payload to test for XSS vulnerability. • wordpress / composer / npm: N/A - Alf.io is not a WordPress plugin or Node.js package. • database (mysql, redis, mongodb, postgresql): N/A - This vulnerability does not directly impact the database. • windows / supply-chain: N/A - Alf.io is not a Windows application or supply-chain component.

1. 2024-02-16Disclosure

   disclosure

1. 予約済み2024-02-08
2. 公開日2024-02-16
3. 更新日2024-08-26
4. EPSS 更新日2026-04-02

The recommended mitigation for CVE-2024-25627 is to immediately upgrade Alf.io to version 2.0-M4-2402 or later. Since no workarounds are provided by the vendor, upgrading is the only viable solution. Before upgrading, it is advisable to back up the Alf.io database and configuration files to facilitate a rollback if necessary. After the upgrade, verify the fix by attempting to upload an HTML file containing a simple JavaScript alert payload through the administrative interface. The payload should be blocked or sanitized, confirming the vulnerability has been addressed.