Zimperium zLabs has brought to light a thorough examination of the security and privacy measures in place across 800 free VPN apps for both Android and iOS platforms. The findings are alarming, presenting a landscape riddled with vulnerabilities that jeopardize the privacy and security of users extensively.
Critical Security Flaws
The analysis revealed that many of these VPN apps fall short in providing genuine privacy protection. They not only request excessive permissions, often beyond what should be necessary for their advertised functions, but many also rely on outdated or compromised third-party libraries. A noteworthy discovery was that some apps still employ versions of libraries susceptible to the infamous Heartbleed vulnerability, a bug that had been addressed but not universally adopted, leaving personal data at risk of interception.
Furthermore, about 1% of these apps were found vulnerable to Man-in-the-Middle attacks due to improper certificate validation. This flaw allows potential attackers the ability to intercept and potentially decrypt users' data.
Issues with Compliance and Permissions
On the iOS front, approximately 25% of the apps examined failed to adhere to basic privacy guidelines set out by Apple, lacking valid privacy manifests or providing misleading data collection disclosures. This non-compliance poses a significant issue, particularly as apps increasingly request permissions unrelated to VPN functionality. On Android devices, permissions such as AUTHENTICATE_ACCOUNTS and READ_LOGS are often sought, while iOS users encounter requests for continuous location tracking and local network discovery, each carrying its own implications for user privacy.
The implications of these permissions are profound, especially for organizations employing BYOD (Bring Your Own Device) policies. VPN apps that are compromised due to these vulnerabilities could lead to severe risks, including credential theft and unauthorized access within networks, setting the stage for data breaches and loss.
To counter these risks, Zimperium recommends a rigorous vetting process for mobile apps, including both static and dynamic analyses, prior to any deployment. This would involve detecting any excessive permissions, privacy leaks, and unsecured implementation practices to fortify against these vulnerabilities.



