CVE-2021-30858highunder attackCWE-416

CVE-2021-30858: high-severity vulnerability in Apple iOS

Published · Updated

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76Vexday Risk Score

Prioritize patching. It under exploitation confirmed by CISA and has a public proof of concept.

ssvc Actcvss 8.8epss 13%
from disclosure to weapon51 days
Published on NVDAug 24
1st PoC+51d
CISA KEV+71d
What the vendors declare (VEX)

Official vendor statements in CSAF/VEX format: whether their product is affected, already fixed, or ruled out — and why. These are the vendor's assertions, not Vexday's judgment.

Red HatVEX document ↗
Affected
2 products (9 components)
Red Hat Enterprise Linux 7 · Red Hat Enterprise Linux 6
workaround: This flaw can be mitigated by either disabling JavaScript or by disabling IndexedDB
Fixed
10 products (411 components)
Red Hat Enterprise Linux AppStream EUS (v. 8.2) · Red Hat Enterprise Linux AppStream EUS (v. 8.1) · Red Hat Enterprise Linux AppStream (v. 8) · Red Hat Enterprise Linux Client (v. 7) · Red Hat Enterprise Linux Client Optional (v. 7) · and others 5
fix ↗
Not affected
1 product (5 components) — because the vulnerable code is not present in the product
Red Hat Enterprise Linux 9
Action required by CISAfederal deadline: 2021-11-17

Apply updates per vendor instructions.

In short

A memory vulnerability in Apple's WebKit allows attackers to execute arbitrary code by sending specially crafted web content to iPhones, iPads, or Macs. This flaw was actively exploited in the wild before the fix.

Technical detail

Use-after-free vulnerability in WebKit's memory management; triggered by processing maliciously crafted web content without requiring user interaction beyond viewing a webpage. Exploitation results in arbitrary code execution with the privileges of the affected process; patched in iOS 14.8, iPadOS 14.8, and macOS Big Sur 11.6.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. 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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products
Apple · iOSApple · macOS
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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