What Users Must Do Now to Stay Safe After WhatsApp Zero-Click Exploit

Update Immediately to Block CVE-2025-55177

WhatsApp has released patched versions for iOS and macOS (2.25.21.73 and later for iOS, 2.25.21.78 for Mac). Users should update immediately through the App Store or WhatsApp’s official site. Automatic updates should be enabled to ensure future patches are applied without delay.

Apply Apple’s Latest Security Fixes

The WhatsApp flaw was chained with Apple’s CVE-2025-43300 ImageIO bug in targeted campaigns. To close the entire attack chain, iPhone and Mac users must install Apple’s latest iOS and macOS security updates. Delaying leaves devices exposed even if WhatsApp is up to date.

Enable iPhone Lockdown Mode (For High-Risk Users)

Apple’s Lockdown Mode—available on recent iOS and macOS versions—significantly reduces the attack surface by blocking risky features such as message parsing and link previews. Journalists, activists, lawyers, and government officials should enable this feature to harden devices against spyware.

Audit Device Security

Users should review app permissions, disable unused services, and check for unusual activity such as:

• Rapid battery drain
• Overheating without cause
• Unexpected data usage
• Strange background processes

These may signal compromise and should trigger further forensic checks.

Use Defense-in-Depth

While updates are the most effective protection, layering defenses helps reduce exposure:

• Install mobile security apps that monitor for unusual behavior
• Back up data regularly in case of compromise
• Use encrypted communications and avoid untrusted links or files

Expert Insight

“Mobile messaging apps have become part of critical infrastructure,” said El Mostafa Ouchen, cybersecurity author and analyst. “A zero-day in WhatsApp is not just a tech problem—it’s a national security issue. Updating quickly and adopting layered defenses is essential.”

Bottom Line

The WhatsApp zero-click exploit was highly targeted and not used at mass scale, but it underscores the fragility of mobile security. The best defense is simple: update now, turn on automatic updates, and practice ongoing vigilance.