CVE-2019-17421 in OpManager
Summary
by MITRE
Incorrect file permissions on the packaged Nipper executable file in Zoho ManageEngine OpManager 12.4.072 and Firewall Analyzer 12.4.072 allow local users to elevate privileges to root by overwriting this file with a malicious payload.
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Analysis
by VulDB Data Team • 02/26/2024
The vulnerability identified as CVE-2019-17421 represents a critical privilege escalation flaw within Zoho ManageEngine OpManager and Firewall Analyzer products at version 12.4.072. This issue stems from improper file permission configuration on the packaged Nipper executable component, which creates an exploitable condition that allows local attackers to gain root-level system access. The affected software packages contain a binary file that should normally be protected from modification by regular users but instead maintains permissions that permit arbitrary file overwrites. This misconfiguration enables attackers to substitute the legitimate Nipper executable with a malicious payload designed to execute with elevated privileges. The vulnerability operates under the principle of insecure file permissions, which is categorized under CWE-732, where inadequate access control permissions are assigned to critical system files.
The technical exploitation mechanism relies on the attacker's ability to identify and manipulate the vulnerable Nipper executable file within the software installation directory. When a local user can overwrite this file, they can inject malicious code that will execute with the privileges of the process that runs the Nipper binary. Since the Nipper utility is likely designed to perform network scanning or analysis functions, it typically runs with elevated privileges to access network interfaces and system resources. The attack vector demonstrates a classic privilege escalation pattern where an attacker leverages a poorly configured file permission to gain unauthorized system-level access. This flaw aligns with ATT&CK technique T1068 which describes the exploitation of legitimate credentials and system utilities to escalate privileges. The vulnerability essentially creates a backdoor through which malicious code can be executed with root privileges, bypassing normal access controls.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete system control over affected installations. Once root access is obtained, attackers can modify system configurations, install persistent backdoors, exfiltrate sensitive data, and compromise the integrity of the entire network monitoring infrastructure. The affected systems become vulnerable to further attacks, including lateral movement within the network, as the attacker now possesses the highest level of system permissions. Organizations running these specific versions of Zoho ManageEngine products face significant risk exposure, particularly in environments where these tools are used for critical network monitoring and security operations. The vulnerability affects not just individual systems but potentially entire network infrastructures that rely on these monitoring solutions for security posture management. The flaw also impacts the principle of least privilege enforcement, as the software fails to properly isolate system utilities from unauthorized modification attempts.
Mitigation strategies for CVE-2019-17421 require immediate remediation through official software updates provided by Zoho ManageEngine. Organizations should prioritize applying the vendor-supplied patches that address the incorrect file permissions on the Nipper executable. In the interim, system administrators should manually verify and correct file permissions on the affected executable to prevent overwrite operations by non-privileged users. The recommended approach includes implementing restrictive file permissions such as 755 or 644 for system executables and ensuring that only authorized system accounts can modify these files. Additionally, organizations should implement monitoring for unauthorized file modification attempts and establish regular permission audits to detect similar misconfigurations. Security controls should include privilege separation, where system utilities run with minimal necessary permissions, and the implementation of file integrity monitoring solutions to detect unauthorized changes to critical system binaries. The vulnerability highlights the importance of proper software security practices during development and deployment phases, emphasizing the need for automated permission checks and security scanning tools to prevent similar issues in future releases.