CVE-2016-5109 in Worx Home
Summary
by MITRE
Citrix Worx Home for iOS before 10.3.6 and XenMobile MDX Toolkit for iOS before 10.3.6 might allow physically proximate attackers to bypass in-application Apple Touch ID authentication via unspecified vectors, related to an application requiring re-authentication.
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Analysis
by VulDB Data Team • 02/24/2019
The vulnerability described in CVE-2016-5109 represents a critical security flaw in Citrix Worx Home for iOS and XenMobile MDX Toolkit for iOS versions prior to 10.3.6. This issue specifically targets the authentication mechanisms within mobile applications, creating a pathway for attackers who are physically present near the target device to circumvent the built-in Touch ID security features. The flaw exists in the application's re-authentication process, which should have enforced continuous authentication but instead allowed unauthorized access through unspecified attack vectors. This type of vulnerability directly impacts the principle of least privilege and can be classified under CWE-287, which deals with improper authentication mechanisms in applications. The security implications extend beyond simple credential theft to encompass potential data breaches and unauthorized access to corporate resources that these mobile applications typically protect.
The technical exploitation of this vulnerability occurs when an attacker with physical proximity to a device running vulnerable Citrix applications can bypass the Touch ID authentication process that should require re-authentication after certain events or time intervals. The unspecified vectors suggest that the flaw may involve timing attacks, session management issues, or improper handling of authentication state transitions within the application framework. This weakness allows attackers to maintain access to applications that should require periodic re-authentication, effectively creating a persistent backdoor. The vulnerability's impact is particularly concerning given that Touch ID is designed as a secure authentication mechanism that should provide a high level of assurance for device access and application usage. Attackers could leverage this flaw to access sensitive corporate data, perform unauthorized transactions, or maintain persistent access to enterprise applications without the need for additional credentials or authentication factors.
The operational impact of CVE-2016-5109 extends significantly beyond the immediate technical breach, as it undermines the fundamental security posture of organizations relying on Citrix mobile application solutions for enterprise mobility management. Organizations using affected versions of Worx Home and MDX Toolkit could experience unauthorized access to corporate applications, sensitive data exposure, and potential lateral movement within their networks. The vulnerability creates a persistent threat vector that does not require network access or complex attack chains, making it particularly dangerous in environments where physical security controls may be insufficient. This flaw directly relates to the ATT&CK technique T1550.001 which covers legitimate credentials and T1550.002 which addresses use of stolen credentials, as the vulnerability enables unauthorized access without requiring traditional credential compromise. The attack surface is broadened by the fact that this affects mobile application frameworks that are commonly used in enterprise environments for secure remote access and application delivery.
Organizations should immediately implement the vendor-provided security patches for Citrix Worx Home and XenMobile MDX Toolkit to address this vulnerability, as the affected versions are no longer supported with security updates. The mitigation strategy should include comprehensive testing of the updated applications in controlled environments before full deployment to ensure compatibility with existing enterprise systems. Security teams should also conduct thorough vulnerability assessments of their mobile application environments to identify any other instances where similar authentication bypass flaws may exist. Additional compensating controls such as enhanced mobile device management policies, application whitelisting, and regular security monitoring should be implemented to reduce the risk exposure. The vulnerability highlights the importance of maintaining up-to-date mobile application security controls and demonstrates the critical need for continuous security assessment of enterprise mobility solutions. Organizations should also consider implementing additional authentication layers beyond Touch ID, such as multi-factor authentication, to provide defense in depth against similar vulnerabilities that may be discovered in the future.