CVE-2021-42002 in ADManager Plus
Summary
by MITRE • 11/11/2021
Zoho ManageEngine ADManager Plus before 7115 is vulnerable to a filter bypass that leads to file-upload remote code execution.
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Analysis
by VulDB Data Team • 11/12/2021
The vulnerability identified as CVE-2021-42002 affects Zoho ManageEngine ADManager Plus version 7115 and earlier, representing a critical security flaw that combines filter bypass mechanisms with remote code execution capabilities. This vulnerability resides within the application's file upload functionality, where inadequate input validation and filtering controls allow malicious actors to circumvent security restrictions. The flaw enables unauthorized users to upload malicious files that can subsequently be executed within the application's environment, potentially leading to complete system compromise.
The technical implementation of this vulnerability stems from insufficient validation of file upload filters within the ADManager Plus application. Attackers can exploit this weakness by crafting specially formatted files or manipulating upload parameters to bypass the intended security restrictions. This filter bypass occurs at the application layer where file type validation should occur, allowing arbitrary file uploads that could contain malicious payloads. The vulnerability aligns with CWE-434, which describes insecure file upload conditions where applications accept files without proper validation of their content or type. The flaw represents a classic example of how inadequate input sanitization can lead to privilege escalation and remote code execution scenarios.
The operational impact of CVE-2021-42002 extends beyond simple unauthorized file uploads, as it provides attackers with a pathway to execute arbitrary code on the target system. Once successful, this vulnerability allows threat actors to gain full control over the affected server, potentially leading to data exfiltration, system compromise, and lateral movement within the network. The vulnerability affects organizations using older versions of ADManager Plus, which are commonly deployed in enterprise environments for Active Directory management. This creates significant risk for organizations that may not have implemented timely patching procedures or maintained current software versions.
Mitigation strategies for CVE-2021-42002 primarily focus on immediate remediation through software updates to version 7115 or later, which contains the necessary security patches. Organizations should also implement additional protective measures such as network segmentation to limit access to the affected application, enhanced monitoring of file upload activities, and regular security assessments of web applications. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in application design. Security teams should also consider implementing web application firewalls and content filtering solutions to detect and prevent malicious upload attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving file execution and privilege escalation, highlighting the need for comprehensive defensive measures across multiple attack phases. Organizations must also establish robust patch management processes to prevent similar vulnerabilities from remaining unaddressed in their infrastructure.