CVE-2004-0614 in osTicket
Summary
by MITRE
osTicket trusts a hidden form field in the submit form to limit the upload size of a document, which could allow remote attackers to upload a file of any size.
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Analysis
by VulDB Data Team • 05/23/2019
The vulnerability identified as CVE-2004-0614 resides within the osTicket support ticket system, specifically targeting the file upload functionality. This critical security flaw stems from the application's improper validation of user-supplied data, where the system relies on a hidden form field to enforce file size limitations. The hidden field mechanism represents a fundamental security weakness that directly violates secure coding principles and industry best practices for input validation.
The technical implementation of this vulnerability demonstrates a classic case of insecure input validation where the application trusts client-side data without proper server-side verification. When users attempt to submit files through the ticketing system, the application checks the value of a hidden form field to determine whether the upload should be permitted based on size constraints. However, this hidden field can be easily manipulated by remote attackers who have no legitimate need to upload large files. The flaw allows adversaries to bypass the intended upload size limits by simply modifying the hidden field value, effectively removing all restrictions on file uploads. This represents a failure in the principle of least privilege and demonstrates the absence of proper access control mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, creating a potential vector for various malicious activities including denial of service attacks through large file consumption, storage exhaustion, and possible code execution if the system processes uploaded files without proper sanitization. Attackers could leverage this vulnerability to flood the system with massive files, consuming available disk space and potentially causing system crashes or making the support ticket system unavailable to legitimate users. The vulnerability also opens the door to potential exploitation of other related security flaws that may exist in the file handling components of the application.
From a cybersecurity perspective, this vulnerability aligns with CWE-1004 which addresses insecure validation of input parameters, and represents a clear violation of the principle of input validation as outlined in the OWASP Top Ten. The flaw also corresponds to ATT&CK technique T1190 which involves exploiting vulnerabilities in web applications to gain unauthorized access or execute malicious code. Organizations utilizing affected versions of osTicket face significant risk of compromise, particularly in environments where the support ticket system is accessible to untrusted users or where the application handles sensitive data.
Mitigation strategies for this vulnerability require immediate implementation of server-side validation controls that do not rely on client-supplied data for enforcing upload restrictions. System administrators should implement proper input validation mechanisms that verify file sizes against server-side configuration limits regardless of hidden form field values. The recommended approach involves implementing robust server-side checks that validate file size limits independently of any client-side parameters, ensuring that all file uploads are subject to the same size restrictions regardless of how the form is submitted. Additionally, organizations should consider implementing additional security measures such as file type validation, content scanning, and proper access controls to prevent unauthorized use of the file upload functionality. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other components of the application stack.