CVE-2019-3568

A buffer overflow (CWE-122) in the VoIP telephony stack of WhatsApp allowed a remote attacker to achieve remote code execution on a target device by sending a specially crafted series of RTCP packets to the victim's phone number. Because the flaw resided in the call-handling stack of the core app, an attacker who could reach the target's phone number over the network could gain arbitrary code execution on the device. All WhatsApp users at the time of disclosure were potentially exposed, since the vulnerable component shipped in the mainstream Meta Platforms (then Facebook) product rather than an optional add-on. The vulnerability was added to CISA's Known Exploited Vulnerability catalog on 2022-04-19, indicating confirmed real-world exploitation, and its EPSS score of 39.2% (99th percentile) signals a high likelihood of continued exploitation; no public proof-of-concept is known. It was remediated in vendor updates issued in 2019 and is widely associated with targeted espionage use (notably Pegasus spyware deployments).

What to do: Update WhatsApp on all mobile devices to the latest vendor release, per the CISA KEV required action; inventory your mobile fleet for outdated 2019-era builds and verify current app versions. Prioritize high-value targets (executives, journalists, government personnel) given the vulnerability's confirmed in-the-wild exploitation in espionage campaigns. No public PoC is known, but the flaw is remotely exploitable via network packets to a phone number, so treat patching as urgent.