CVE-2020-10962 in PowerShell App Deployment Toolkit
Summary
by MITRE • 08/01/2023
In PowerShell App Deployment Toolkit (aka PSAppDeployToolkit) through 3.8.0, an incorrect access control vulnerability in the default configuration may allow an authenticated user to potentially enable escalation of privilege via local access.
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Analysis
by VulDB Data Team • 08/23/2023
The PowerShell App Deployment Toolkit represents a widely used framework for deploying applications through PowerShell scripts, with version 3.8.0 containing a critical access control vulnerability that significantly impacts system security. This vulnerability resides in the default configuration of the toolkit and specifically affects the permissions model that governs how local users interact with deployed applications. The flaw stems from improper privilege management within the toolkit's installation and execution processes, creating a potential pathway for authenticated users to escalate their privileges locally. The vulnerability is particularly concerning because it leverages the trust model inherent in the default toolkit configuration, where legitimate users with basic access rights can exploit misconfigured permissions to gain elevated system privileges. This issue affects organizations that rely on the toolkit for enterprise application deployment, as the default settings create an environment where privilege escalation can occur without additional security controls.
The technical flaw manifests through improper access control mechanisms within the toolkit's file and registry permissions, where default installations may grant unnecessary write permissions to local user accounts. This misconfiguration allows authenticated users to modify critical deployment components or registry entries that should only be accessible to administrators or system processes. The vulnerability specifically relates to how the toolkit handles temporary files, installation directories, and registry keys during the application deployment process. When default settings are maintained, the toolkit creates files and directories with permissions that permit local users to modify or replace critical components, creating a privilege escalation vector. This flaw can be exploited through various means including file replacement attacks, registry modification, or by leveraging the toolkit's own deployment scripts to execute malicious code with elevated privileges. The root cause involves inadequate privilege separation and improper default permission settings that fail to follow the principle of least privilege.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain persistent access to systems and potentially compromise entire networks. An authenticated user who exploits this vulnerability can deploy malicious applications, modify system configurations, or establish backdoors that persist across system reboots. The toolkit's widespread adoption in enterprise environments means that this vulnerability affects numerous organizations simultaneously, creating a significant attack surface. Once escalated, attackers can leverage the elevated privileges to perform actions such as installing additional malware, modifying system security settings, or accessing sensitive data that was previously protected by standard user permissions. The vulnerability is particularly dangerous in environments where the toolkit is used for deploying applications with elevated privileges, as the attack surface expands significantly. The impact is further amplified by the fact that many organizations may not be aware of the default configuration issues, leading to prolonged exposure periods where the vulnerability remains unaddressed.
Organizations should implement immediate mitigations including reviewing and hardening the default toolkit configurations, applying the latest security patches from the toolkit maintainers, and implementing additional access controls to limit user privileges during application deployment processes. The recommended approach involves configuring proper file and registry permissions that restrict write access to authorized personnel only, implementing mandatory access controls, and conducting regular security audits of toolkit installations. Security teams should also consider implementing application whitelisting policies and monitoring for suspicious deployment activities that might indicate privilege escalation attempts. The vulnerability aligns with common attack patterns documented in the attack tree model where initial access through legitimate user accounts can be escalated to system-level privileges through misconfigured permissions. This flaw demonstrates the importance of secure configuration management and proper privilege segregation as outlined in cybersecurity frameworks such as the NIST Cybersecurity Framework and ISO 27001 standards. Organizations should also consider implementing network segmentation and monitoring solutions to detect and prevent exploitation attempts. The mitigation strategies should include regular security assessments of deployment toolkits and maintaining updated security configurations that align with the principle of least privilege as defined in security best practices and industry standards.