CVE-2018-7807 in Data Center Expert
Summary
by MITRE
Data Center Expert, versions 7.5.0 and earlier, allows for the upload of a zip file from its user interface to the server. A carefully crafted, malicious file could be mistakenly uploaded by an authenticated user via this feature which could contain path traversal file names. As such, it could allow for the arbitrary upload of files contained with the zip onto the server file system outside of the intended directory. This is leveraging the more commonly known ZipSlip vulnerability within Java code.
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Analysis
by VulDB Data Team • 04/16/2020
The vulnerability identified as CVE-2018-7807 affects Data Center Expert versions 7.5.0 and earlier, presenting a critical security risk through its file upload functionality. This flaw enables authenticated users to exploit a path traversal vulnerability within the application's zip file handling mechanism, effectively allowing arbitrary file uploads to locations outside the intended directory structure. The vulnerability specifically leverages the well-documented ZipSlip vulnerability pattern, which has been extensively catalogued in the CWE database under CWE-502 as "Deserialization of Untrusted Data" and more specifically related to path traversal issues. The attack vector involves a maliciously crafted zip file containing filenames with directory traversal sequences such as "../" that can bypass normal file upload restrictions.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the Java-based file processing code. When the application extracts files from uploaded zip archives, it fails to properly sanitize the filenames contained within the archive, allowing attackers to specify arbitrary paths that can result in files being written outside the designated upload directory. This represents a classic path traversal vulnerability that has been documented in numerous security advisories and forms part of the ATT&CK framework's technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1078.004 for "Valid Accounts: Cloud Accounts" when such vulnerabilities are exploited to establish persistent access. The vulnerability is particularly dangerous because it requires only authenticated access, meaning that users with legitimate credentials can exploit this flaw to potentially execute malicious code or gain unauthorized access to the server's file system.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, as it can enable attackers to execute arbitrary code on the target system. Successful exploitation could allow threat actors to upload web shells, backdoor executables, or other malicious payloads that could compromise the entire system. The vulnerability affects the application's integrity and availability, as attackers could potentially overwrite critical system files or create persistent access points through the uploaded malicious files. Organizations using Data Center Expert versions 7.5.0 or earlier face significant risk of data breaches, system compromise, and potential lateral movement within their network infrastructure. The vulnerability's exploitation aligns with ATT&CK technique T1021.001 for "Remote Services: Remote Desktop Protocol" and T1059.001 for "Command and Scripting Interpreter: PowerShell" when attackers use the uploaded files to establish command and control capabilities. This vulnerability also represents a failure in the principle of least privilege, as authenticated users can escalate their privileges through file system manipulation, potentially leading to complete system compromise.
Mitigation strategies for CVE-2018-7807 should include immediate patching of the Data Center Expert application to version 7.5.1 or later, which addresses the underlying ZipSlip vulnerability in the Java code. Organizations should implement strict input validation for all file upload operations, including comprehensive sanitization of filenames and path components to prevent directory traversal attempts. The application should enforce strict directory restrictions during zip file extraction, ensuring that all extracted files are confined to the intended directory structure regardless of the paths specified within the zip archive. Network segmentation and access controls should be implemented to limit the impact of potential exploitation, while monitoring and logging of file upload activities should be enabled to detect suspicious behavior. Security teams should also consider implementing Web Application Firewalls (WAF) rules specifically designed to detect and block path traversal attempts in file upload operations, and regular security assessments should be conducted to identify similar vulnerabilities in other applications within the organization's infrastructure. The vulnerability highlights the importance of secure coding practices and proper input validation, particularly when handling user-supplied data in file processing operations, aligning with industry standards such as OWASP Top 10 A04:2021 - "Insecure Design" and the CWE categories related to path traversal and file handling vulnerabilities.