CVE-2021-30666

HIGH KEV

iOS 12.5.3 - Code Execution via Malicious Web Content

Title source: manual

Exploitation Summary

CVE-2021-30666 is actively exploited and listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added November 3, 2021.

Description

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

References (2)

Core 2

Core References

Release Notes, Vendor Advisory x_refsource_misc

https://support.apple.com/en-us/HT212341

Third Party Advisory, US Government Resource

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30666

Scores

CVSS v3 8.8

EPSS 0.0118

EPSS Percentile 79.2%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment

Exploitation active

Automatable no

Technical Impact total

Details

CISA KEV 2021-11-03

VulnCheck KEV 2021-05-03

InTheWild.io 2021-05-03

ENISA EUVD EUVD-2021-17583

CWE

CWE-119

Status published

Products (1)

apple/iphone_os < 12.5.3

Published Sep 08, 2021

KEV Added Nov 03, 2021

Tracked Since Feb 18, 2026