CVE-2017-11561 in ManageEngine OpManager
Summary
by MITRE
An issue was discovered in ZOHO ManageEngine OpManager 12.2. An authenticated user can upload any file they want to share in the "Group Chat" or "Alarm" section. This functionality can be abused by a malicious user by uploading a web shell.
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Analysis
by VulDB Data Team • 06/14/2020
The vulnerability identified as CVE-2017-11561 resides within ZOHO ManageEngine OpManager version 12.2, specifically affecting the Group Chat and Alarm sections of the application. This issue represents a critical authorization and input validation flaw that allows authenticated users to upload arbitrary files to the system. The vulnerability stems from insufficient file type validation mechanisms within the upload functionality, creating an avenue for privilege escalation and potential system compromise. Attackers can exploit this weakness to bypass normal security restrictions that should prevent the upload of executable or malicious content.
The technical implementation of this vulnerability involves the absence of proper file extension filtering and content validation within the file upload handlers. When users attempt to upload files through the Group Chat or Alarm sections, the application fails to adequately verify the file types being submitted. This lack of validation creates a path for malicious actors to upload web shells or other executable payloads that can be executed within the application's environment. The vulnerability specifically affects the application's file handling capabilities and demonstrates poor input sanitization practices that violate fundamental security principles.
The operational impact of CVE-2017-11561 extends beyond simple unauthorized file uploads, as it enables a malicious user to gain persistent access to the underlying system. Once an attacker successfully uploads a web shell, they can execute arbitrary commands on the server, potentially leading to full system compromise. This vulnerability can be leveraged to establish backdoors, exfiltrate sensitive data, or use the compromised system as a staging ground for further attacks within the network. The authenticated nature of the vulnerability means that attackers do not require administrative privileges to exploit the flaw, making it particularly dangerous in environments where user access is not strictly controlled.
Security practitioners should implement multiple layers of defense to mitigate this vulnerability, including strict file type validation, content inspection, and proper access controls. The vulnerability aligns with CWE-434, which describes insecure file upload conditions, and represents a clear violation of the principle of least privilege. Organizations should also consider implementing network segmentation and monitoring for unusual file upload activities. From an ATT&CK framework perspective, this vulnerability maps to T1059 for command and script injection, and T1078 for valid accounts, as it allows attackers to leverage legitimate user accounts to execute malicious code. Regular security assessments and patch management procedures are essential to prevent exploitation of this class of vulnerability, which remains relevant in contemporary application security contexts where file upload functionality continues to present significant attack surfaces.