November 3, 2021 · Applied Cybernetics Group
CVE-2021-30663 — Apple Multiple Products
Apple Multiple Products WebKit Integer Overflow Vulnerability
- Added to KEV
2021-11-03- Federal due date
2021-11-17- Vendor
- Apple
- Product
- Multiple Products
- EPSS
- 76.8th percentile (score 0.010, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2021-30663
CISA short description
Apple iOS, iPadOS, macOS, tvOS, and Safari WebKit contain an integer overflow vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Required action
Apply updates per vendor instructions.