CVE-2021-30951Network attack vector

Arbitrary code execution via WebKit use-after-free

Published Aug 24, 2021 · Updated Aug 3, 2024

WebKit use-after-free in iOS and iPadOS before 15.2, macOS before 12.1, and watchOS before 8.3 allows attackers to execute code via web content. WebKit retains or dereferences an object after its memory has been freed while processing attacker-controlled page content; Apple has not disclosed the affected function or object type. Exploitation requires the target to process the crafted content, and resulting code runs in the WebKit process context rather than inherently with kernel privileges.

CVSS severity8.8
High
EPSS probability2.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

WebKit use-after-free in iOS and iPadOS before 15.2, macOS before 12.1, and watchOS before 8.3 allows attackers to execute code via web content. WebKit retains or dereferences an object after its memory has been freed while processing attacker-controlled page content; Apple has not disclosed the affected function or object type. Exploitation requires the target to process the crafted content, and resulting code runs in the WebKit process context rather than inherently with kernel privileges.

The record

CVE
CVE-2021-30951
Published
Aug 24, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <15.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <15.2
Apple · macOSversion=unspecified <12.1; version=unspecified <15.2
Apple · watchOSversion=unspecified <8.3

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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