WhatsApp may expose the OS you use to run it – which could expose you to crooks

Researchers at Zengo disclosed that WhatsApp's multi-device implementation exposes persistent identity-key metadata with platform-specific formats (e.g., 32-character Android IDs, 20+4 iPhone prefix, 18-character Windows IDs), enabling attackers to fingerprint users' operating systems and linked devices and potentially choose the most vulnerable target for malware. Zengo reported the issue to Meta, which acknowledged the submission but did not provide a timetable for a remediation.