Threats / Apple / CVE-2021-30665
CVE-2021-30665
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Apple Multiple Products vulnerability
WebKit memory corruption vulnerability in Apple platforms enabling remote code execution through malicious web content processing.
Verdict
Today item — known-exploited.
Out-of-bounds write in WebKit HTML parsing allows unauthenticated remote attackers to execute arbitrary code by delivering crafted web content to vulnerable browsers and applications on iOS, iPadOS, macOS, watchOS, and tvOS.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
8 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
Probability (EPSS)
EPSS 0.03471 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Apple, Multiple Products. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-787 Out-of-bounds Write — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
Craft malicious HTML or web content designed to trigger out-of-bounds memory write in WebKit parser
Business
Exposure of user devices across Apple ecosystem to arbitrary code execution without user interaction beyond visiting compromised or attacker-controlled web pages
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Deliver payload through compromised websites, advertisements, or phishing campaigns targeting Safari and WebKit-dependent applications
Business
Potential compromise of user data, credentials, and device integrity across consumer and enterprise deployments
3
Lateral reach — past segmentation narrative 3
Attacker
Execute arbitrary code with browser process privileges to establish persistence or lateral movement
Business
Risk of widespread device compromise affecting Apple's platform security reputation and user trust
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05