Zero-Day Mobile Vulnerabilities: Why Speed is the Key to Cyber Defense

Every year, mobile devices become more powerful, more innovative, and more complex. That’s good news for diligent workers who want to stay connected and productive. Unfortunately, it’s also good news for threat actors who want to steal sensitive data. Zero-day vulnerabilities in mobile applications and operating systems (OSs) are becoming more common over time. When cyber criminals exploit these vulnerabilities, organizations can be spied on, unknowingly leak sensitive data, or even lose their ability to do business.

Fortunately, patching a zero-day vulnerability doesn’t have to be a fire drill every time. With some proactive cybersecurity measures, you can discover and patch mobile vulnerabilities — minimizing patch latency and the window of time threat actors have to use them against you. However, once you become aware of a vulnerability, you’ll have to act fast.

If you stay abreast of the latest threat intelligence and keep your organization’s mobile devices up to date, you can keep your valuable data secure. If not, you risk a costly and compromising data breach.

Zero-day vulnerabilities on mobile platforms

What are zero-day vulnerabilities? As a brief refresher, zero-day vulnerabilities are security holes in a piece of software that went undetected during the prerelease phase. If an app, or OS version has an exploitable flaw once it goes live, that’s a zero-day vulnerability. These vulnerabilities may let threat actors compromise entire systems through privilege escalation, remote code execution, or malware installation.

Once a piece of software has a zero-day vulnerability, there are a few potential outcomes:

• Best-case scenario: Security researchers discover the flaw and disclose it directly to the developer. The developer puts out a patch ASAP, then discloses the vulnerability after the threat has passed.
• Neutral scenario: Researchers don’t discover the vulnerability, but neither do threat actors. The flaw remains fixable — or exploitable — in the future.
• Worst-case scenario: Threat actors discover the vulnerability and find a way to exploit it in the wild. Developers create a patch, but only after the damage is done.

All three of these scenarios happen in real life. In June 2025, for example, Google disclosed three zero-day Android vulnerabilities that cyber criminals had actively exploited. In the same month, though, Google also explained and patched more than 30 flaws that could have been just as dangerous. It’s impossible to tell how many of these vulnerabilities might go unnoticed in the apps we use every day.

Discovering zero-day vulnerabilities is an involved process, which may involve code inspection, penetration testing, or reverse-engineering app features. Talented security researchers can build entire careers out of discovering and disclosing these flaws — but so can persistent threat actors.

Zero-day vulnerabilities can be particularly dangerous for mobile devices. Smartphones and tablets are prime targets for malicious apps and phishing scams, which can be easy ways for threat actors to get a foothold. Furthermore, bring-your-own-device (BYOD) policies make it possible for workers to mix professional and personal information. These risks aren’t nearly as severe on company-issued computers, which administrators can lock down more easily.

However, the biggest risk on mobile devices may simply be outdated OS or app versions. While the operating systems that power desktops and laptops may receive support for more than a decade at a time, smartphones and tablets tend to get between one and five years of security patches. Even if a developer patches a zero-day vulnerability on newer devices, a threat actor could still exploit it on older ones.

Defend your organization from zero-day vulnerabilities

By definition, it’s essentially impossible to predict zero-day vulnerabilities. To protect your organization and its sensitive data, the best thing you can do is learn about these flaws as soon as they become public, then take proactive measures to safeguard your employees and their mobile devices.

Patch your apps and operating systems

Installing the latest patches for your mobile apps and operating systems is a good cybersecurity practice in general, but it’s even more important when a zero-day vulnerability is involved. When security researchers disclose zero-day vulnerabilities, they often discuss exactly how the flaw worked and how a threat actor could have exploited it. If you don’t install patches as soon as they become available, an attacker might essentially have a step-by-step guide for compromising your devices.

However, there are a few reasons why patching can’t be your only defense against zero-day flaws. First, mobile apps and operating systems don’t always install these updates automatically. Users can put off patching their systems for days or weeks at a time, and the phone or tablet will continue to function as normal.

Second, there’s no guarantee that the patch will work properly with your organization’s current deployment. You’ll need time to test the updated software, and your employees may need to continue using the old version in the interim. Complementing software updates with other cybersecurity strategies can be a useful approach.

Adopt a zero-trust approach

The modern kill chain can easily bypass digital firewalls and traditional antivirus software. Modern threat actors often target mobile devices with phishing, smishing, or whaling (executive impersonation) attacks. They can also craft malicious websites that specifically exploit known zero-day vulnerabilities, tricking users with shortened links or URLs that are just a few characters off from the real thing. If a threat actor captures a staff member’s login credentials with one of these techniques, telling them apart from a legitimate user could be difficult. 

In the past, organizations used perimeter-based cybersecurity to block out attackers with digital firewalls. Enterprise antivirus software used a signature-based approach to detect and block known malware. These approaches can still be valuable, but they’re not enough to thwart the modern kill chain. By exploiting zero-day vulnerabilities, threat actors can use legitimate login credentials and trusted devices to compromise systems.

A zero-trust approach to cybersecurity assumes that every login could be from a threat actor, even if a user provides a correct username and password. Users have to verify their identity repeatedly, including through multi-factor authentication (MFA), frequent logins, and familiar locations. Even then, their access to particularly sensitive data might be restricted.

Monitor real-time threat intelligence

Security researchers discover dozens of new vulnerabilities for both Android and iOS every few months. To learn about these flaws, you can use a threat intelligence database — and to really cover your bases, you’ll probably want to consult more than one. These resources gather information about the latest cyber threats, including zero-day vulnerabilities, and often recommend countermeasures for them.

If you see a vulnerability that affects an app or device you use, you can start patching as soon as it’s practical for your organization. If a patch isn’t available yet, you may be able to uninstall the software in question or use different devices in the meantime. Threat intelligence can be part of a proactive detection strategy, in which you continuously monitor your network for novel threats or suspicious behaviors.

Train your staff

Many zero-day vulnerabilities can compromise devices wholesale, but some others require input from a legitimate user. Teach your staff to practice good cybersecurity habits, including:

• Not responding to social engineering messages
• Avoiding suspicious or copycat apps
• Denying apps that request additional privileges
• Ignoring pairing requests from unknown devices

With a standardized reporting procedure, your employees can become both an additional layer of security and a frontline source of threat intelligence.

Protect your data with mobile EDR

While there’s no single cybersecurity strategy that protects against all zero-day vulnerabilities, you can protect your organization’s vital resources with multiple, overlapping methods. In addition to proactive patching and threat intelligence research, you can use a mobile endpoint detection and response (EDR) solution. The Lookout Mobile EDR Playbook explains how our cybersecurity tools can detect threats, evaluate device risks, and help keep your data safe from even the most sophisticated threat actors.