SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-24043

A missing bound check in RTCP flag parsing code prior to WhatsApp for Android v2.21.23.2, WhatsApp Business for Android v2.21.23.2, WhatsApp for iOS v2.21.230.6, WhatsApp Business for iOS 2.21.230.7, and WhatsApp Desktop v2.2145.0 could have allowed an…

CRITICAL 9.1EPSS 1.09%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A missing bound check in RTCP flag parsing code prior to WhatsApp for Android v2.21.23.2, WhatsApp Business for Android v2.21.23.2, WhatsApp for iOS v2.21.230.6, WhatsApp Business for iOS 2.21.230.7, and WhatsApp Desktop v2.2145.0 could have allowed an out-of-bounds heap read if a user sent a malformed RTCP packet during an established call.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
1.09% probability · 65th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-125
Affected
whatsapp/whatsapp · whatsapp/whatsapp business
Source
cve-assign@fb.com
EPSS trend
0%3%5%26 October 2026: 1.09%26 October 202626 October 2026

EPSS 1.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.