The flaw impacted premium Samsung models across the Galaxy S22, S23, and S24 generations as well as the Galaxy Z Fold 4 and Galaxy Z Flip 4. Unit 42 found that attackers could embed malicious data into DNG image files, disguising them with .jpeg extensions to appear legitimate and avoid suspicion. These files could be delivered through everyday communication channels such as WhatsApp, where users are accustomed to receiving shared photos. Because the exploit required no clicks and relied solely on the image being processed, even careful users were at risk.
Once installed, spyware leveraging Landfall could obtain access to sensitive data stored on the device, including photos, contacts, and location information. It was also capable of recording audio and collecting call logs, giving attackers broad surveillance capabilities. The targeting appeared focused primarily on users in the Middle East, with infections detected in countries such as Iraq, Iran, Turkey, and Morocco. Samsung was first alerted to the exploit in September 2024 and issued a patch in April, closing the zero-day vulnerability across affected devices.
The seriousness of the flaw prompted the U.S. Cybersecurity and Infrastructure Security Agency (CISA) to place CVE-2025-21042 in its Known Exploited Vulnerabilities catalog, a list reserved for security issues actively abused in attacks. Federal agencies have been instructed to ensure that any vulnerable Samsung devices under their management are updated no later than December 1st, reflecting the urgency of mitigation efforts.
For consumers, the incident underscores the importance of maintaining strong cybersecurity habits on mobile devices. Regularly updating the operating system is one of the most effective defenses against emerging exploits, as patches often include protections for newly discovered vulnerabilities. Users are also encouraged to be cautious regarding unsolicited content, including media files sent from unknown contacts, and to avoid clicking links or downloading attachments they cannot verify.
Security experts additionally recommend using reputable mobile security tools alongside Google Play Protect to strengthen device defenses. Many modern Android antivirus apps offer supplementary safeguards such as phishing alerts, VPN access, and warnings about malicious websites.
Zero-day attacks remain an unavoidable challenge in the smartphone landscape, as cybercriminals continually look for undiscovered flaws to exploit. But with proactive device updates and careful online behavior, users can significantly reduce their exposure to threats like Landfall and help ensure their personal data remains secure.
