HIGHCVSS v3.1 8.8Actively exploited · CISA KEV since 2021-11-03Vulnerability

CVE-2021-30663

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.

Properties

Euvd product
macOS
Vulnerability name
Apple Multiple Products WebKit Integer Overflow Vulnerability
First seen
2025-10-21T23:25:34+00:00
Cvss score
8.8
Epss score
0.03521
Last seen
2026-10-19T12:00:27+00:00
Due date
2021-11-17
Euvd assigner
apple
Retrieved at
2026-10-21T01:24:47+00:00
Exploited euvd since
2021-11-03T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2021-11-03
Score
8.8
Euvd base score version
3.1
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Apple
Cvss vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
In Signal since
initial import (Sep 2026)
Euvd base score
7.8

Related Entities (8)

AFFECTS_PRODUCT (5)

→[Product]cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*

DESCRIBES (1)

←[KEVEntry]Apple Multiple Products WebKit Integer Overflow Vulnerability

HAS_WEAKNESS (1)

→[Weakness]Integer Overflow or Wraparound

INVOLVES (1)

←[Signal]kev_added · 2021-11-03

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CVE-2021-30663 (CVSS v3.1 8.8) — Ninja Signal Threat Intelligence | Ninja Signal