CVE-2021-20172 in Genie Installer
Summary
by MITRE • 12/31/2021
All known versions of the Netgear Genie Installer for macOS contain a local privilege escalation vulnerability. The installer of the macOS version of Netgear Genie handles certain files in an insecure way. A malicious actor who has local access to the endpoint on which the software is going to be installed may overwrite certain files to obtain privilege escalation to root.
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Analysis
by VulDB Data Team • 01/05/2022
The vulnerability identified as CVE-2021-20172 represents a critical local privilege escalation flaw within the Netgear Genie Installer for macOS systems. This security weakness affects all known versions of the software and stems from improper handling of specific files during the installation process. The vulnerability exists in the installer component that manages file operations, creating an opportunity for malicious actors to exploit the system's trust model and elevate their privileges from standard user level to root access. The flaw specifically manifests when the installer processes certain files in a manner that does not adequately validate file permissions or ownership, allowing for potential manipulation by local attackers.
The technical implementation of this vulnerability involves the installer's failure to properly secure file operations during the installation sequence. When the Netgear Genie Installer executes, it processes various system files and directories without sufficient access control validation. This insecure file handling creates opportunities for attackers to substitute legitimate files with malicious counterparts or manipulate existing files in ways that bypass normal permission checks. The installer's design does not enforce proper file integrity checks or validate that files are being written to locations where the current user has appropriate permissions. According to CWE classification, this vulnerability maps to CWE-276, which describes improper file permissions, and CWE-73, which covers improper neutralization of special elements used in file names. The flaw essentially creates a path traversal or file overwrite condition where attacker-controlled files can be placed in system directories with elevated privileges.
From an operational perspective, this vulnerability presents a significant risk to macOS endpoints where Netgear Genie software is installed. The attack vector requires only local access to the target system, making it particularly dangerous in environments where physical access or remote desktop sessions are possible. An attacker with standard user privileges who can influence the installation process or manipulate files during installation can gain complete system control. This privilege escalation allows the malicious actor to execute arbitrary code with root privileges, potentially leading to complete system compromise, data exfiltration, or establishment of persistent backdoors. The vulnerability impacts organizations that deploy Netgear Genie software across their macOS infrastructure, particularly in enterprise environments where such network management tools are commonly used. The low attack complexity combined with high impact makes this vulnerability particularly attractive to threat actors, as it requires minimal prerequisites and provides maximum reward in terms of system access.
The mitigation strategies for CVE-2021-20172 should focus on immediate remediation through official vendor patches, while also implementing additional security controls. Organizations should ensure they have updated to the latest version of Netgear Genie Installer where the vulnerability has been addressed by the vendor. System administrators should also consider implementing file integrity monitoring solutions to detect unauthorized changes to critical system files during installation processes. The ATT&CK framework categorizes this type of vulnerability under T1068, which covers 'Exploitation for Privilege Escalation', and T1548, which covers 'Abuse of Windows Installer'. Security teams should also review and harden the installation process for all third-party software, ensuring that installation procedures enforce proper file permissions and validate file integrity before execution. Network segmentation and access control measures can help limit the potential impact if an attacker successfully exploits this vulnerability. Additionally, organizations should conduct regular security assessments of their installed software to identify and remediate similar insecure file handling practices across their technology stack.