CVE-2016-1579 in UDM
Summary
by MITRE
UDM provides support for running commands after a download is completed, this is currently made use of for click package installation. This functionality was not restricted to unconfined applications. Before UDM version 1.2+16.04.20160408-0ubuntu1 any confined application could make use of the UDM C++ API to run arbitrary commands in an unconfined environment as the phablet user.
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Analysis
by VulDB Data Team • 09/06/2023
The vulnerability described in CVE-2016-1579 represents a critical privilege escalation flaw within the Ubuntu Device Manager (UDM) system, which is integral to the Ubuntu Touch operating system's package management infrastructure. This vulnerability specifically targets the command execution mechanism that UDM employs to handle post-download operations, particularly for click package installations. The UDM system was designed to provide a controlled environment for package management while maintaining security boundaries between confined and unconfined applications. However, a fundamental design flaw allowed confined applications to bypass these security restrictions and execute arbitrary commands in an unconfined environment with elevated privileges.
The technical flaw stems from the lack of proper access control and privilege enforcement within the UDM C++ API implementation. Confined applications, which are typically restricted to operate within sandboxed environments to prevent unauthorized system access, were able to leverage the UDM API to invoke command execution capabilities that should have been restricted to privileged system components only. This oversight created an attack vector where malicious or compromised confined applications could escalate their privileges and execute commands as the phablet user, which typically possesses significant system access rights. The vulnerability specifically affected UDM versions prior to 1.2+16.04.20160408-0ubuntu1, indicating that the issue was present in the Ubuntu Touch 16.04 release cycle and represented a regression in security controls.
The operational impact of this vulnerability is severe as it fundamentally undermines the security model of Ubuntu Touch's confinement architecture. An attacker could exploit this vulnerability to execute arbitrary commands with elevated privileges, potentially leading to complete system compromise. The phablet user context provides access to system resources and services that are normally protected from confined applications, making this a critical escalation path. This vulnerability could enable attackers to install malicious packages, modify system files, access sensitive data, or establish persistent backdoors on affected devices. The attack surface is particularly concerning given that click packages are the standard method for installing applications on Ubuntu Touch, meaning that any application installed through the normal package management process could potentially be exploited to gain unauthorized system access.
The security implications extend beyond simple privilege escalation to encompass broader system integrity concerns, as this vulnerability effectively allows attackers to bypass the fundamental security boundaries that separate user applications from system services. From a cybersecurity perspective, this vulnerability aligns with CWE-276, which addresses improper privileges, and represents a classic example of insufficient access control. The ATT&CK framework would classify this as a privilege escalation technique, specifically leveraging API abuse to execute commands with elevated privileges. Mitigation strategies should include immediate patching of affected systems to the fixed UDM version, implementation of additional access controls around the C++ API, and monitoring for unauthorized command execution patterns. Organizations should also consider implementing runtime application protection measures and regular security assessments to identify similar vulnerabilities in other system components that may provide similar privilege escalation pathways.