CVE-2021-30809Public exploitNetwork attack vector

Code execution via WebKit use-after-free

Published Oct 28, 2021 · Updated Aug 3, 2024

Use-after-free in WebKit in Apple Safari, iOS, iPadOS, and tvOS before 15 and watchOS before 8 allows remote attackers to execute code. Apple has not published the affected WebKit function; the engine accesses freed memory while processing maliciously crafted web content. Exploitation requires user interaction with attacker-controlled content, and successful memory corruption permits code execution in the WebKit process.

CVSS severity8.8
High
EPSS probability1.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in WebKit in Apple Safari, iOS, iPadOS, and tvOS before 15 and watchOS before 8 allows remote attackers to execute code. Apple has not published the affected WebKit function; the engine accesses freed memory while processing maliciously crafted web content. Exploitation requires user interaction with attacker-controlled content, and successful memory corruption permits code execution in the WebKit process.

The record

CVE
CVE-2021-30809
Published
Oct 28, 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. Oct 28, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <15
Apple · Safariversion=unspecified <15
Apple · tvOSversion=unspecified <15
Apple · watchOSversion=unspecified <8

Published CVSS scores

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

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

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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