Android vs iPhone Security: Why No System is 100% Secure

When I went to the CYBERUS Spring School in early April 2025 (April 7–11, 2025, at Université Bretagne Sud in Lorient, France), one of the topics we talked about was the age old query: Which phone is safer, the iPhone or the Android? The conversations were instructive to me as a security enthusiast. We discussed technical ideas like mobile app sandboxing and even how two apps from the same developer could access data in spite of platform security measures. The discussions underlined an important realization I've had over the years: while IOS and Android both have robust security mechanisms, neither is completely impenetrable. In this essay, I'll provide a professional (but hopefully easy-to-read) analysis of Android vs iPhone security, interspersed with my own viewpoints, demonstrating why no system can claim perfect security.

Security by Design: IOS and Android Approaches

Apple's IOS and Google's Android have fundamentally different approaches to device security.  Apple's IOS is often praised for its "walled garden" approach.  It's a closed environment, with Apple closely controlling hardware, software, and apps.  Every app is thoroughly tested before being published, system updates are delivered swiftly to all compatible devices, and the integration of hardware and software enables sophisticated data protection measures such as the Secure Enclave and Touch/Face ID.  Apple's strict App Store restrictions and app sandboxing make it difficult for malware to survive on IOS.  In reality, IOS has been less susceptible to large-scale malware outbreaks than other platforms.  However, this does not mean it is fully impervious to attacks (bitdefender.com). Apple’s locked-down approach raises the bar for attackers, yet determined adversaries still find cracks. (More on that soon.)

On the other side, Google's Android promotes openness and flexibility. Android is open-source and runs on a wide range of devices from many manufacturers. This means consumers have a wider range of devices to choose from, as well as the ability to install software from sources other than the official Play Store, but security can be unequal. Various manufacturers have varied update schedules, and the presence of third-party app stores or sideloading increases the danger. Android's openness has historically resulted in a higher volume of malware attacking it. According to one analysis, Android users are "50 times more likely" to be infected with malware than iPhone users, with an estimated 97% of all mobile malware targeting (androidsilentbreach.com). 

The reasons aren't just that Android is "less secure" intrinsically; market share and ecosystem differences play a significant role. Google has made significant advances in security. For example, Google Play Protect now analyzes apps for viruses, and Android also uses robust encryption and verified boot. However, if users are not cautious, the open paradigm will unavoidably result in a larger baseline risk (qualysec.com).

App sandboxing is a vital security feature used to contain vulnerabilities on both IOS and Android. In our Spring School session, we discussed a lot about sandboxing, which means that each app runs in its own isolated environment with limited access to other apps' data. This design stops malicious apps from readily stealing data from other apps or the operating system. For example, an iPhone app cannot simply read data from another app's storage; the same is true for Android. According to one security comparison, "IOS uses a sandboxing mechanism that restricts each app's access to the device's resources and limits the amount of data users can share between apps," and Android, "uses a sandboxing mechanism to restrict each app's access... and limit the amount of data users can share between apps," tooefani.com. In other words, both platforms are structured such that apps, by default, reside in separate little silos (efani.comefani.com).

However, there are exceptions and nuances. Both operating systems provide controlled ways for apps to share data (for example, on IOS, apps from the same developer can use App Groups or shared keychain access, and on Android, apps can opt to have a shared user ID or use custom permissions to share data). These are intended features, say, to let a suite of apps from one company work together, but they must be implemented carefully. At the Spring School, I found it fascinating when we discussed how a developer (or attacker) could potentially exploit these mechanisms. For instance, if two Android apps are signed with the same developer key and configured with a shared user ID, they essentially act as one, sharing a sandbox. That’s great if you trust both apps (e.g., a trusted company’s apps sharing login info), but it could be a liability if a bad actor somehow gained the same signature or if one app is compromised. The takeaway here is that the sandbox model greatly improves security, but it’s not an impenetrable wall, especially when design features allow for controlled data sharing that might be abused if one isn’t vigilant.

When Big Companies (and Hackers) Find Loopholes

Even with strong sandboxing and policies, real-world actors often find creative ways to bypass security boundaries on both Android and IOS. An eye-opening example I want to discuss is recent research by the “Local Mess” team, which uncovered a covert tracking method used by tech giants Meta (Facebook) and Yandex on Android devices (localmess.github.io). This wasn’t a typical malware attack, but rather an intentional misuse of platform features for tracking purposes. Essentially, Facebook and Instagram (and Yandex’s apps) were found silently listening on certain localhost network ports on the device. Meanwhile, their web scripts (like the Facebook Pixel embedded on websites, or Yandex Metrica analytics script) would communicate with these apps via the device’s loopback network interface.

What does that mean in plain terms? 

Imagine you visit a website on your Android phone’s browser, and that site has Facebook’s tracking pixel. Normally, a website can’t just reach into your Facebook app data due to sandboxing. But Meta discovered a trick: they ran a little server inside the Facebook app (listening on 127.0.0.1, the phone’s own loopback address). The Pixel script on the web page would send a piece of data (like your unique Facebook tracking cookie _fbp) to that local address on a specific port. If the Facebook or Instagram app were running in the background on your phone, it would receive that data. In effect, this bridged the gap between the browser and the native app, allowing Facebook to link what you do on the web with who you are in the app (localmess.github.io). Yandex apps were doing something similar with their analytics. This clever (and creepy) method allowed companies to de-anonymize users’ web browsing by tying it to their app identities. And because it used standard, permitted networking calls to localhost, it bypassed normal privacy safeguards; clearing your cookies or using incognito mode wouldn’t stop it, and Android’s permission system had no say in the matter. Perhaps even worse, this technique could have been exploited by malicious apps too, not just the intended company apps, since any app could listen on those same ports to siphon data.

For Example, A simplified depiction of Meta’s and Yandex’s web-to-app tracking technique on Android. JavaScript from a website (left side) sends identifying data (like cookies or IDs) to a listening port on the device’s loopback network. The native app (right side, e.g., Facebook or a Yandex app) picks up that data and links it with the user identifiers it holds, then sends it to its server. This method effectively bridges the sandbox between the browser and the app. Such abuse of legitimate OS capabilities bypassed typical protections (like cookie clearing and incognito mode) until it was caught and reported in 2025.

When I first read about this on Local Mess, I was both impressed and concerned. It reminded me of our Spring School discussion about apps from the same developer sharing data. Here, a similar concept was at play: code from the same company running in different contexts (web and app) colluding to share data. The concept we discussed in our session was a bit different (that was more about two apps on a device), but the spirit is the same: if you control multiple components (in this case a web script and a phone app), you can sometimes find unexpected paths to make them talk to each other despite the OS’s isolation measures. Meta and Yandex basically found a loophole in Android’s system behavior, and they took advantage of it (until it was disclosed and patched around mid-2025).

What about iPhones? The good news is that this localhost monitoring method did not have a direct impact on IOS. The researchers discovered no evidence that the same approach was being employed on IOS. IOS browsers (which all use WebKit) could theoretically accomplish similar things (WebKit allows connecting to localhost, and an IOS app can listen on a port), but Apple's restrictions and architecture make it more difficult for an app to run covert background listeners, as Android apps can. Apple may also have tougher app review procedures that would detect something unusual, such as an app activating a listening port for non-standard reasons. In this situation, iPhone users looked to be safe from Meta and Yandex's small experiment (localmess.github.io). However, this is a theme I want to stress; just because IOS isn’t vulnerable to one particular exploit doesn’t mean it’s bulletproof.

In fact, IOS has had its fair share of significant security breaches, particularly targeted ones. A well-known example is the Pegasus spyware (created by NSO Group), which notoriously employs zero-click iMessage exploits to remotely infect iPhones. Victims would not need to press anything; an iMessage containing malicious material might discreetly corrupt the device. Despite Apple's efforts to patch such vulnerabilities, Pegasus and related tools have succeeded by exploiting unknown flaws in IOS messaging and image processing code (bitdefender.com). If you want to learn more about Pegasus, check out my YouTube video.

According to Bitdefender's security specialists, the tightly controlled ecosystem of IOS reduces the likelihood of broad malware breakouts, but state-sponsored attackers have resorted to more advanced approaches like as zero-day and zero-click attacks. Spyware like Pegasus used these hidden IOS weaknesses to install itself undetected, revealing that determined attackers can breach even Apple's (barriers.bitdefender.com). Apple has had to push release updates for IOS zero-day vulnerabilities several times in recent years due to exploits actively being used in the field, according to the Hacker News website. In short, the iPhone's security approach is effective at blocking generic malware and nuisances, but it is not impregnable, particularly against well-funded enemies or spy agencies.

Meanwhile, Android continues to be a playground for a lot of the world’s malware (from adware to banking trojans), largely because of its openness and huge user base. There are indeed more “everyday” threats on Android malicious apps that sneak into third-party app stores or even occasionally the Play Store, phishing attacks aiming at Android users, etc. The flip side is that Android’s openness also enables a great deal of security innovation and user control (for example, advanced users can install firewall apps, antivirus, or even custom secure versions of Android like GrapheneOS). But one has to exercise caution and good security hygiene on Android, perhaps more proactively. I often tell friends: if you stick to the Google Play Store and keep your phone updated, Android’s security is quite robust for day-to-day use. Problems arise when users sideload apps from unknown sources or when manufacturers stop providing updates, leaving devices with unpatched bugs. For some Android phones, “security updates” can feel like a privilege, not a right, a reality that can make a two-year-old Android phone more vulnerable if the vendor abandons it. iPhones, by contrast, tend to get IOS updates for many years, which is a significant security advantage in Apple’s favor.

Which One Should You Choose (and Stay Safe)?

After examining the landscape, here’s my honest opinion: There is no simple, universal answer as to whether iPhones or Androids are “more secure”; it really depends on how you use them and what threats you’re most concerned about. Both platforms have matured a lot in security.

• If you’re an average user who sticks to official app stores and just wants a device that securely works, Apple’s iPhone may give you a slight peace of mind advantage. The closed ecosystem means it’s harder for you (or malicious actors) to mess things up. Malware on iPhones is exceedingly rare compared to Android. Apple’s tight control generally reduces the risk of rogue apps; indeed, iPhone users are much less likely to encounter malware unless they jailbreak their device or do something out of the ordinary. As one report summed up, the stricter controls make iPhones “less prone to threats,” though not entirely immune (avpsuite.combitdefender.com). IOS is a bit like a secure appliance, safe by design for most people, as long as you keep it updated.  
• If you value flexibility and customization, or you’re a tech-savvy user who doesn’t mind taking extra steps for security, Android is a perfectly viable choice; you just have to be a little more vigilant. The fact that 97% of mobile malware targets Android (silentbreach.com) sounds scary, but remember that much of that malware lives outside the Play Store, in the darker corners of the internet, or preys on users who click on shady links. By avoiding untrusted apps and keeping your phone updated, you mitigate a lot of that risk. In return, Android offers benefits like a choice of hardware at various price points, deeper control over the system, and the ability to install powerful security tools. I personally use an iPhone with IOS and a tablet with Android as my daily driver, and I do so confidently, but I also practice good security habits (I limit app permissions, install system updates as soon as they’re out, and only download apps from reputable sources).
   
  

It’s also worth noting that the threat models differ between the platforms. If your main concern is mass-market malware or adware, those tend to loom larger on Android (simply due to ecosystem scale and openness). On the other hand, if you’re a high-profile individual worried about targeted spyware or sophisticated hacks, IOS has been a prime target of those (because a lot of VIPs use iPhones and breaking into IOS can yield high-value access). For example, we saw Meta (Facebook) itself become a victim in a way, not of a security flaw per se, but WhatsApp (owned by Meta) was exploited by NSO Group’s spyware in the past (darkreading.com), which led to a lawsuit. And numerous journalists and activists have been targeted via iPhone exploits in iMessage or FaceTime. So again, no system has a monopoly on security: each has strengths and each has high-impact weaknesses that have been exploited in the wild.

So, which should you choose? 

My advice is: choose the platform that fits your needs and comfort, but use it wisely. If you go Android, maybe stick with well-supported models (e.g., Google’s Pixel phones or Samsung’s, which get frequent security updates) and be mindful of what you install. If you go iPhone, enjoy the strong default security but don’t become complacent, stay on top of updates and be aware that “secure” doesn’t mean “invincible.” In both cases, basic best practices go a long way: use a strong passcode, enable 2FA for your accounts, keep your software updated, and think before installing something or clicking a link.

Final Thoughts: No 100% Security

One phrase that came up repeatedly during the Spring School and in daily security work is that there is no such thing as 100% secure. This applies to mobile phones as much as any technology. IOS and Android each implement industry-leading security measures, yet each continues to have vulnerabilities discovered every year, some of which get patched quietly, and some of which make headlines. Security is a process, not a permanent state. As our devices get more secure, attackers adapt; it’s an arms race that likely won’t end.

On the bright side, both Google and Apple have very talented security teams and have created mobile platforms that are light-years ahead of where they were a decade ago. For the average person, both an updated Android phone and an updated iPhone offer high levels of security suitable for most uses. The differences start to matter more in edge cases, specific threat scenarios, or if one platform’s approach aligns better with your personal preferences on privacy and control.

From my perspective, after hashing it out at a week-long Spring School and keeping up with the latest research, the “Android vs iPhone” security debate isn’t about declaring an absolute winner. Instead, it's about understanding how they differ and acknowledging that any complex system can be broken under the right conditions. Rather than asking “which is 100% safe?”, it's better to ask “how can I use whichever device I have as safely as possible?”. Whether you carry an iPhone or an Android, knowing the limitations of your device’s security and staying informed (like you are by reading this blog!) is key.

In the end, I have friends who swear by their iPhone’s security and others who trust Android with some hardening tweaks, and you know what? Both camps have valid points. My personal take: I love the freedom Android gives to us, but I respect the polish and security-focused design of IOS as well. And I’ll continue keeping an eye on research (like the Local Mess findings) that exposes how companies or attackers find those sneaky ways around protections. It’s a reminder that we must stay vigilant. No system is perfectly secure, but with knowledge and good practices, we can get pretty close to secure enough for our daily lives, and that’s a win for all of us who just want our data to stay in the right hands.

References:

• Local Mess disclosure on Meta and Yandex’s covert tracking technique - localmess.github.io
• Bitdefender report highlighting that while iOS’s walled garden limits malware, it’s “not invulnerable” to advanced threats - bitdefender.com
• Example of Pegasus spyware using zero-click iMessage exploits on iPhones - bitdefender.com
• Silent Breach analysis noting Android malware prevalence (97% of mobile malware targeting Android) - silentbreach.com
• Efani security comparison describing sandboxing on iOS and Android - efani.comefani.com