Virtual private networks have become a go-to for many users to hide their IP and circumvent geoblocks, but when the service is free, the bill often comes in the form of data. Several recent analyses indicate that Free VPNs can compromise privacy and the safety of those who install them, often without them being aware of it.
The problem is neither isolated nor minor: they have been detected Technical glitches, opaque business models, and intrusive permissions potentially affecting millions of people. Cybersecurity experts warn that “free” is financed with collection and exploitation of information, aggressive advertising integrations or even more dangerous practices.
What researchers have discovered
A technical report from Zimperium zLabs examined nearly 800 VPN apps mobile phones, divided equally between iOS and Android, and found a repeated pattern: poor privacy, unnecessary permissions and code with known vulnerabilities.
The findings include that the 25% of iOS VPNs lack a valid privacy policy and that around 6% request privileged permissions that they shouldn't need. In addition, older versions of OpenSSL were found to be affected by Heartbleed (CVE-2014-0160) and cases of incorrect certificate validations, which open the door to man-in-the-middle (MITM) attacks.
The impact goes beyond personal use: in work environments with personal devices, poorly maintained VPNs can become the weak link in corporate security (BYOD), exposing sensitive data due to poor development and maintenance hygiene.
In parallel, the Open Technology Fund's VPN Transparency Report analyzed 32 commercial providers and detected serious problems in popular services such as TurboVPN, VPN Proxy Master, XY VPN or 3X VPN – Smooth Browsing, some with more than 100 million downloadsAmong the practices reported, the use of technologies such as Shadow Socks presented as strong encryption, despite not being designed for that purpose.
Kaspersky experts emphasize that many free VPNs work as "bait" to attract trusting users: behind it there may be anything from massive data monetization to the exploitation of devices in botnets, as documented in previous incidents.
Common practices in free VPNs
- Excessive permissions: On Android, requests like READ_LOGS or AUTHENTICATE_ACCOUNTS give access to system logs and account management; on iOS, background geolocation is seen and access to the local network without clear justification.
- Registration and sale of data: The “free and unlimited” model is usually based on telemetry, tracers and agreements with third parties to monetize traffic or even the bandwidth of user.
- Weak or simulated encryption: outdated libraries (vulnerable OpenSSL) and poor certificate validations allow MITM attacks and leaks.
- Legal opacity: incomplete or absent privacy policies and lack of external audits to verify promises like the No-Logs policy.
In some cases attempts to use private permissions on iOS, deep access to system functions that go beyond public APIs. While the system doesn't always grant them, the mere request is already a alarm signal.
Cases and figures that are worrying
A recent NordVPN survey in the United Kingdom indicates that the 12% of users continues to rely on free services, despite the fact that the general level of knowledge about VPNs is around 80%Among the reasons are savings and the search for quick solutions for specific needs.
Specialists point to added risks: suppliers with state ties opaque, weak protocols that leave users sold out Public Wi-Fi and app store ratings that prioritize ease of use over privacy guarantees. When it is promised "free and unlimited”, the reality is usually the data monetization, bandwidth reselling or aggressive upselling.
Several technical analyses have documented the use of outdated third-party libraries, including the residual presence of Heartbleed and issues of certificate pinning that facilitate MITM attacks. These are basic flaws that should not persist in software designed to protect communications.
Added to this is the case of Mobdro Pro IP TV + VPN, an app that circulated outside of Google Play and acted as an installer of the banking Trojan Klopatra. Through social engineering, the attackers obtained permissions from the Accessibility Services to take control of the device, steal credentials and operate accounts; have been documented around 3.000 infections and the use of two botnets for its propagation.
Additional risks on Android and iOS
On Android, some VPN clients ask for READ_LOGS (reading records) and AUTHENTICATE_ACCOUNTS (account and token management). Permissions like this can open the door to leaks of sensitive data already a detailed mapping of user activity. The side loading It also increases exposure to malicious campaigns.
On iOS, requests have been observed for persistent location and access to the local network that allow you to silently scan nearby devices. Adding to this problem is the lack of transparency: some of the apps analyzed did not include an adequate privacy statement, which prevents informed consent.
Incorrect certificate validation and absence of certificate pinning Cash facilitates man-in-the-middle attacks, degrading the supposedly “secure connection” into a vulnerable channel. If we add to that obsolete cryptographic code, the risk multiplies.
For businesses with BYOD policies, a poor VPN can be a operational risk: : It only takes one vulnerable client for credentials, communications or corporate data to be exposed.
Recommendations for navigating wisely
The general pattern of experts is clear: avoid free VPNsThere are rare exceptions, with public audits, but they are not the norm. To reduce risks, it is advisable to opt for services with audited No-Logs policy, legal transparency and independent reviews.
- Check audits and jurisdiction: Seek external validation of No-Logs, publish clear legal responsibility and data retention policies.
- Check permissions before accepting: denies geolocation in the background and access to the local network if they're not justified. Be wary of requests that aren't the purpose of a VPN.
- Demand modern encryption: prioritizes protocols such as WireGuard or OpenVPN and avoid “proxies” sold as encryption.
- Install only from official stores: Avoid unverified sources and read the Privacy Policy in detail; look for independent white papers and reviews.
- Configure the app correctly: Activate your own kill switch and DNS, limit telemetry and keep the client updated.
The accumulated evidence leaves little room for doubt: when a service promises protection at zero cost, the actual payment is often your dataBetween technical vulnerabilities, opaque policies, and abusive permissions, free VPNs can expose millions; educating yourself, reviewing each permission, and choosing audited and transparent providers is the best way to protect yourself. shield your privacy no surprises.
