CVE-2016-5765 in Host Access Management
Summary
by MITRE
Administrative Server in Micro Focus Host Access Management and Security Server (MSS) and Reflection for the Web (RWeb) and Reflection Security Gateway (RSG) and Reflection ZFE (ZFE) allows remote unauthenticated attackers to read arbitrary files via a specially crafted URL that allows limited directory traversal. Applies to MSS 12.3 before 12.3.326 and MSS 12.2 before 12.2.342 and RSG 12.1 before 12.1.362 and RWeb 12.3 before 12.3.312 and RWeb 12.2 before 12.2.342 and RWeb 12.1 before 12.1.362 and ZFE 2.0.1 before 2.0.1.18 and ZFE 2.0.0 before 2.0.0.52 and ZFE 1.4.0 before 1.4.0.14.
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Analysis
by VulDB Data Team • 06/12/2019
The vulnerability described in CVE-2016-5765 represents a critical directory traversal flaw affecting multiple Micro Focus products including Host Access Management and Security Server MSS, Reflection for the Web RWeb, Reflection Security Gateway RSG, and Reflection ZFE applications. This security weakness stems from inadequate input validation within the administrative server components of these applications, allowing remote attackers to manipulate URL parameters and access files outside the intended directory structure. The flaw specifically enables attackers to read arbitrary files through crafted URLs that exploit limited directory traversal capabilities, potentially exposing sensitive system information, configuration files, and potentially confidential data stored on the affected servers. The vulnerability affects specific version ranges across multiple product lines, with patches available for each affected release, highlighting the widespread nature of this particular security weakness.
The technical implementation of this vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. Attackers can exploit this weakness by crafting malicious URLs that include directory traversal sequences such as "../" or similar constructs to navigate outside the intended web root directory and access files that should remain restricted. The administrative server components in question likely process user-supplied URL parameters without proper sanitization or validation, allowing the traversal sequences to be interpreted as legitimate directory navigation commands. This type of vulnerability typically arises from insufficient input validation, where the application fails to properly validate or sanitize user-provided data before using it in file system operations. The limited nature of the traversal suggests that while attackers can access files outside the intended directory, they may be constrained by the application's specific implementation and the underlying file system permissions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it could potentially allow attackers to access sensitive configuration files, log files, or other system artifacts that might contain credentials, system information, or other valuable data. The remote unauthenticated nature of the attack means that any attacker with access to the network can exploit this vulnerability without requiring valid credentials, making it particularly dangerous for publicly exposed administrative interfaces. Organizations running affected versions of these Micro Focus products face significant risk of unauthorized access to their systems, potentially leading to further exploitation opportunities including privilege escalation, data exfiltration, or system compromise. The vulnerability affects multiple product lines within the Micro Focus ecosystem, indicating a systemic issue that required coordinated patching across different software components, and underscores the importance of maintaining up-to-date security patches for enterprise applications.
The remediation approach for this vulnerability involves applying the vendor-provided patches and updates for each affected product version, as specified in the CVE description. Organizations should prioritize patching their installations of MSS 12.3 before 12.3.326, MSS 12.2 before 12.2.342, RSG 12.1 before 12.1.362, RWeb 12.3 before 12.3.312, RWeb 12.2 before 12.2.342, RWeb 12.1 before 12.1.362, ZFE 2.0.1 before 2.0.1.18, ZFE 2.0.0 before 2.0.0.52, and ZFE 1.4.0 before 1.4.0.14. Security administrators should implement comprehensive vulnerability management processes to identify and remediate similar weaknesses in other applications and systems. Additionally, implementing network segmentation, access controls, and monitoring for unusual file access patterns can help detect potential exploitation attempts. This vulnerability demonstrates the importance of input validation and proper access controls in administrative interfaces, as highlighted by ATT&CK technique T1059.007 for command and scripting interpreter and T1078 for valid accounts, since the ability to read arbitrary files without authentication represents a fundamental breakdown in system security controls. Organizations should also consider implementing web application firewalls and input validation mechanisms to prevent similar directory traversal attacks against other web applications in their environment.