CVE-2018-17838 in JTBC(PHP)
Summary
by MITRE
An issue was discovered in JTBC(PHP) 3.0.1.6. Arbitrary file read operations are possible via a /console/#/console/file/manage.php?type=list&path=c:/ substring.
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Analysis
by VulDB Data Team • 03/28/2020
The vulnerability identified as CVE-2018-17838 affects JTBC PHP version 3.0.1.6 and represents a critical security flaw that enables unauthorized file system access through a specific console endpoint. This issue stems from inadequate input validation and access control mechanisms within the web application's file management interface, creating a pathway for attackers to enumerate and potentially read arbitrary files on the server. The vulnerability manifests through a specific URL pattern that allows manipulation of file path parameters, bypassing normal security restrictions that should prevent unauthorized file access.
The technical implementation of this vulnerability involves a flaw in the file management component where the application fails to properly sanitize user-supplied path parameters before processing file system operations. When an attacker constructs a malicious URL with the path parameter set to a specific directory structure such as c:/, the application processes this input without adequate validation, allowing traversal to system directories that should remain protected. This represents a classic path traversal vulnerability that can be classified under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory. The vulnerability exists because the application does not implement proper input sanitization or directory traversal protection mechanisms that would prevent attackers from accessing files outside the intended scope of the application's file management functionality.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with the ability to read arbitrary files from the server filesystem. This could potentially expose sensitive information including configuration files, database credentials, application source code, and other confidential data stored on the server. Attackers could leverage this capability to gain insights into the application architecture, identify additional vulnerabilities, and potentially escalate their attack to achieve full system compromise. The vulnerability specifically targets the console management interface, which typically contains administrative functions and should be protected from unauthorized access, making this a particularly dangerous flaw in a content management system. This type of vulnerability aligns with ATT&CK technique T1213.002, which involves data from information repositories, and represents a critical weakness in the application's defense-in-depth strategy.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and access control measures. The primary fix involves sanitizing all user-supplied path parameters to prevent directory traversal attacks, ensuring that the application validates and restricts file access to predefined directories only. Organizations should implement proper authentication and authorization controls for the console interface, ensuring that only authorized administrative users can access file management functions. Additionally, the application should employ proper path validation techniques that prevent traversal beyond the intended directory boundaries, including implementing whitelisting of allowed paths and rejecting any input that contains suspicious path sequences. System administrators should also consider implementing network-level restrictions to limit access to administrative interfaces, and regularly audit file access logs to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of secure coding practices and proper input validation as outlined in OWASP Top Ten and other industry security standards, emphasizing that applications must never trust user input without proper sanitization and validation.