CVE-2016-2228 in Groupware Webmail Edition
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in horde/templates/topbar/_menubar.html.php in Horde Groupware before 5.2.12 and Horde Groupware Webmail Edition before 5.2.12 allows remote attackers to inject arbitrary web script or HTML via the searchfield parameter, as demonstrated by a request to xplorer/gollem/manager.php.
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Analysis
by VulDB Data Team • 07/24/2022
The CVE-2016-2228 vulnerability represents a critical cross-site scripting flaw in Horde Groupware web applications that affects versions prior to 5.2.12. This vulnerability resides within the template file horde/templates/topbar/_menubar.html.php and specifically targets the searchfield parameter handling mechanism. The flaw enables remote attackers to inject malicious web scripts or HTML content into the application's user interface, creating a significant security risk for organizations utilizing these email and groupware platforms. The vulnerability is particularly concerning as it can be exploited through a direct request to xplorer/gollem/manager.php, which serves as a legitimate application endpoint for managing file systems and resources within the Horde environment.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding within the Horde Groupware framework. When users interact with the search functionality, the application fails to properly sanitize or escape the searchfield parameter before rendering it within the HTML template structure. This omission creates an opening for attackers to inject malicious payloads that execute in the context of other users' browsers. The vulnerability manifests as a classic reflected XSS attack where malicious input is immediately reflected back to users without proper sanitization, allowing for session hijacking, credential theft, or redirection to malicious sites. The flaw aligns with CWE-79, which specifically addresses cross-site scripting vulnerabilities, and demonstrates poor input validation practices that violate fundamental web application security principles.
The operational impact of this vulnerability extends beyond simple script injection, potentially enabling sophisticated attack vectors that can compromise entire user sessions and organizational security postures. An attacker exploiting this vulnerability could gain access to sensitive user data, manipulate email content, or redirect users to phishing sites that appear legitimate within the trusted Horde environment. The attack surface is particularly wide given that Horde Groupware serves as a comprehensive webmail and collaboration platform, meaning that successful exploitation could affect multiple users simultaneously. This vulnerability particularly impacts organizations relying on legacy Horde installations, as the attack requires no privileged access or complex exploitation techniques, making it highly attractive to threat actors seeking to establish persistent access or conduct large-scale phishing campaigns.
Organizations affected by CVE-2016-2228 should implement immediate mitigations including upgrading to Horde Groupware 5.2.12 or later versions where the vulnerability has been patched. The fix typically involves implementing proper input validation and output encoding mechanisms within the affected template files, ensuring that all user-supplied input is sanitized before being rendered in HTML contexts. Additional protective measures include implementing content security policies that restrict script execution, deploying web application firewalls to detect and block malicious payloads, and conducting comprehensive security audits of all web applications to identify similar input validation weaknesses. Security teams should also consider implementing user education programs to recognize and report suspicious email content or unexpected script behavior, as this vulnerability can be exploited through social engineering techniques that leverage the trusted nature of the Horde platform. The remediation process should follow ATT&CK framework guidance for defensive measures against web application attacks, particularly focusing on input validation and output encoding controls that prevent malicious code execution in user contexts.