CVE-2019-9751 in Open Ticket Request System
Summary
by MITRE
An issue was discovered in Open Ticket Request System (OTRS) 6.x before 6.0.17 and 7.x before 7.0.5. An attacker who is logged into OTRS as an admin user may manipulate the URL to cause execution of JavaScript in the context of OTRS. This is related to Kernel/Output/Template/Document.pm.
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Analysis
by VulDB Data Team • 08/01/2023
The vulnerability identified as CVE-2019-9751 affects the Open Ticket Request System OTRS version 6.x prior to 6.0.17 and 7.x prior to 7.0.5, representing a critical cross-site scripting flaw that can be exploited by authenticated administrators. This vulnerability stems from improper input validation within the Kernel/Output/Template/Document.pm component of the application, which processes template rendering for document output. The flaw allows an attacker with administrative privileges to manipulate URL parameters in a manner that results in arbitrary JavaScript execution within the context of the OTRS application, effectively bypassing the application's security controls.
The technical nature of this vulnerability aligns with CWE-79, which describes cross-site scripting flaws occurring when untrusted data is incorporated into web pages without proper validation or encoding. The vulnerability specifically manifests in the template processing mechanism where user-supplied parameters are not adequately sanitized before being rendered in the browser context. This allows an attacker to inject malicious JavaScript code that executes with the privileges of the logged-in administrator, potentially enabling complete system compromise. The issue is particularly concerning because it requires only administrative access to exploit, meaning that a compromised administrator account could immediately be leveraged to execute arbitrary code.
From an operational impact perspective, this vulnerability presents a severe risk to organizations relying on OTRS for ticket management and customer service operations. An attacker with administrative privileges could manipulate the system to redirect users to malicious sites, steal session cookies, or even escalate privileges further within the network. The vulnerability affects the core document rendering functionality of OTRS, potentially compromising all user data and system integrity. The exploitation requires minimal technical skill beyond having administrative access, making it particularly dangerous as it can be leveraged by threat actors who have already gained access to administrative accounts through other means.
Organizations should immediately implement mitigations including applying the vendor-provided patches for versions 6.0.17 and 7.0.5, which address the improper input handling in the template processing module. Network segmentation and privileged access controls should be reinforced to limit administrative access to only necessary personnel, while implementing additional monitoring for unusual URL parameter usage patterns. The ATT&CK framework categorizes this vulnerability under T1059.007 for JavaScript execution and T1548.001 for account manipulation, highlighting the need for comprehensive defensive measures. Additional protective measures include implementing web application firewalls to detect and block suspicious parameter patterns, conducting regular security audits of template processing components, and ensuring that administrative accounts are protected with multi-factor authentication. Organizations should also consider implementing automated vulnerability scanning tools that can detect similar issues in other applications, as this type of vulnerability often indicates broader template processing security weaknesses within web applications.