CVE-2017-12098

Vulnerability

The rails_admin Rails gem version 1.2.0 contains an exploitable cross-site scripting (XSS) vulnerability in the add filter functionality. When a user creates a custom filter through the admin interface, the application generates a URL containing unfiltered user input. A specially crafted URL can inject arbitrary JavaScript into the admin page. This affects the rails_admin gem versions up to and including 1.2.0 as reported by Cisco Talos [1][2][4].

Exploitation

An attacker can craft a malicious URL containing the XSS payload (e.g., by appending a crafted f[] parameter with JavaScript). The attacker then phishes an authenticated admin user into visiting this URL in their browser. No special network position or authentication is required for the attacker beyond the ability to deliver the link. The vulnerability triggers upon page load in the browser, and was confirmed to work in Chrome, Safari, and Firefox [4].

Impact

Successful exploitation allows the attacker to execute arbitrary JavaScript in the context of the victim's authenticated admin session. This can lead to data theft, session hijacking, or unauthorized administrative actions, resulting in partial loss of confidentiality and integrity of the application [1].

Mitigation

As of the available references, a fix for this specific vulnerability in rails_admin 1.2.0 was not explicitly outlined in the disclosure timeline. Users should upgrade to a later version of the rails_admin gem that addresses CVE-2017-12098. If no patched version is available, consider using a Web Application Firewall (WAF) to filter malicious query parameters, restrict the add_filter functionality to trusted users, and sanitize user input in filter parameters. The vulnerability is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog as of this writing.