CVE-2018-7890 in Applications Manager
Summary
by MITRE
A remote code execution issue was discovered in Zoho ManageEngine Applications Manager 13.5. The publicly accessible testCredential.do endpoint takes multiple user inputs and validates supplied credentials by accessing a specified system. This endpoint calls several internal classes, and then executes a PowerShell script. If the specified system is OfficeSharePointServer, then the username and password parameters to this script are not validated, leading to Command Injection.
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Analysis
by VulDB Data Team • 11/12/2024
The vulnerability identified as CVE-2018-7890 resides within Zoho ManageEngine Applications Manager version 13.5, representing a critical remote code execution flaw that can be exploited by attackers without authentication. This vulnerability manifests through the publicly accessible testCredential.do endpoint, which serves as an interface for validating system credentials against specified targets. The endpoint's design incorporates multiple user inputs that are processed through internal classes before executing a PowerShell script, creating a complex attack surface where improper input validation creates exploitable conditions. The flaw specifically occurs when the target system type is configured as OfficeSharePointServer, indicating that the vulnerability is not universal across all supported platforms but rather targeted to specific integration scenarios.
The technical exploitation of this vulnerability stems from insufficient validation of username and password parameters when the OfficeSharePointServer system type is selected. This validation failure creates a command injection vulnerability where attacker-controlled input directly influences the PowerShell script execution. The PowerShell script execution context allows for arbitrary command execution on the underlying system, potentially enabling full system compromise. This vulnerability directly maps to CWE-77 and CWE-94 within the Common Weakness Enumeration framework, representing command injection and code injection weaknesses respectively. The attack vector leverages the principle of least privilege violation, where legitimate administrative functionality becomes a conduit for unauthorized code execution. The vulnerability's impact is amplified by the fact that the endpoint is publicly accessible, eliminating the need for network reconnaissance or privilege escalation within the target environment.
Operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential data exfiltration. Attackers can leverage this vulnerability to execute malicious commands that may include system enumeration, privilege escalation, or installation of persistent backdoors. The PowerShell script execution capability provides attackers with access to Windows system functionalities and potentially network resources that are normally restricted. This vulnerability can enable attackers to move laterally within networks where the Applications Manager is deployed, as the compromised system may have access to additional network resources. The attack chain typically involves sending specially crafted parameters to the testCredential.do endpoint, which then executes the PowerShell script with attacker-controlled arguments, potentially allowing for complete system takeover. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically PowerShell execution, and T1068 for exploit for privilege escalation.
Mitigation strategies for CVE-2018-7890 should prioritize immediate patching of affected Zoho ManageEngine Applications Manager installations to version 13.6 or later, which includes the necessary input validation fixes. Network segmentation should be implemented to restrict access to the testCredential.do endpoint, limiting exposure to trusted network segments only. Input validation controls should be enhanced at the application level to sanitize all user-supplied parameters before processing, particularly for credential fields when OfficeSharePointServer is specified as the target system type. Access controls should be implemented to restrict the functionality of the testCredential.do endpoint to authorized administrative users only, reducing the attack surface. Monitoring and logging should be enhanced to detect anomalous requests to the endpoint, particularly those containing suspicious command injection patterns. Additionally, organizations should consider implementing web application firewalls to filter malicious payloads and conduct regular security assessments of their applications manager installations to identify similar vulnerabilities in other components. The vulnerability demonstrates the critical importance of input validation in web applications and highlights the need for comprehensive security testing of integration points that execute external commands.