An out-of-bounds read was possible in WhatsApp due to incorrect parsing of RTP extension headers. This issue affects WhatsApp for Android prior to 2.18.276, WhatsApp Business for Android prior to 2.18.99, WhatsApp for iOS prior to 2.18.100.6, WhatsApp Business for iOS prior to 2.18.100.2, and WhatsApp for Windows Phone prior to 2.18.224.