CVE-2016-9139 in Open Ticket Request System
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Open Ticket Request System (OTRS) 3.3.x before 3.3.16, 4.0.x before 4.0.19, and 5.0.x before 5.0.14 allows remote attackers to inject arbitrary web script or HTML via a crafted attachment.
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Analysis
by VulDB Data Team • 09/17/2024
The Cross-site scripting vulnerability identified as CVE-2016-9139 affects the Open Ticket Request System OTRS platform across multiple version ranges including 3.3.x before 3.3.16, 4.0.x before 4.0.19, and 5.0.x before 5.0.14. This vulnerability represents a critical security flaw that enables remote attackers to execute malicious web scripts or HTML code within the context of legitimate user sessions. The vulnerability specifically manifests when the system processes crafted attachment files, bypassing normal input validation mechanisms that should prevent such malicious content from being stored or executed within the application environment.
The technical flaw resides in the insufficient sanitization of attachment filenames and content within the OTRS system's file handling processes. When users upload attachments, the platform fails to properly validate and sanitize the attachment metadata, particularly the filename attributes that may contain malicious script code. This weakness allows attackers to craft specially formatted attachment names or content that, when processed by the application, gets executed in the browser context of authenticated users. The vulnerability operates under CWE-79 which specifically addresses Cross-site Scripting flaws in software applications. The attack vector exploits the trust relationship between the web application and its users, where legitimate users unknowingly execute malicious code when viewing or interacting with the compromised attachments.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with the capability to perform session hijacking, steal user credentials, and potentially gain unauthorized access to sensitive ticketing data. Remote attackers can leverage this vulnerability to inject persistent scripts that remain active within the application, allowing for continuous surveillance and data exfiltration. The attack requires minimal privileges as it operates entirely through the web interface without needing direct system access. This vulnerability directly maps to ATT&CK technique T1566 which covers the use of malicious attachments to gain initial access to systems. The compromised environment could lead to privilege escalation and lateral movement within the network, as the attacker's scripts can access session cookies and potentially interact with other system components that share authentication contexts.
Mitigation strategies for CVE-2016-9139 involve immediate patching of affected OTRS versions to their respective secure releases, ensuring that all instances are updated to versions 3.3.16, 4.0.19, or 5.0.14 respectively. Organizations should implement strict input validation measures that sanitize all attachment filenames and content before processing, employing regular expression filtering to remove potentially malicious patterns from attachment metadata. Network segmentation and web application firewalls should be deployed to monitor and block suspicious attachment-related traffic patterns. Additionally, security awareness training for users should emphasize the dangers of opening unexpected attachments, and access controls should be implemented to restrict attachment upload capabilities to authorized personnel only. The vulnerability highlights the importance of proper input validation and output encoding in web applications, demonstrating how seemingly benign file handling operations can become security attack vectors when proper sanitization measures are not implemented.