WhatsApp Buffer Overflow Vulnerability: Under the Scope

This zLabs blog analyzes CVE-2019-3568, a WhatsApp remote code execution vulnerability affecting iOS (and Android) clients: it identifies patched memory-corruption code paths (integer underflow and unchecked memcpy leading to buffer overflows), validates invocation during voice calls via debugger breakpoints, and demonstrates a PoC that an RCE could silently authorize a persistent WhatsApp Web session to hijack an account. The report discusses attacker goals, persistence and stealth trade-offs, and notes that Facebook patched the issue after reports of in-the-wild exploitation.