CVE-2021-30883Known exploitationPublic exploit

Kernel code execution via framebuffer integer overflow

Published Aug 24, 2021 · Updated Oct 21, 2025

Memory corruption in Apple IOMobileFrameBuffer on affected iOS, iPadOS, and macOS releases allows local users to run kernel code. BilerpGainTable::new_from_data performs unchecked 32-bit arithmetic on caller-controlled table dimensions and passes the wrapped size to kalloc_ext, underallocating storage for table data. The AppleCLCD method 78 path is reachable from an app sandbox without special entitlements, enabling kernel compromise; the public proof of concept causes a kernel panic.

CVSS severity7.8
High
EPSS probability14.72%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Apple IOMobileFrameBuffer on affected iOS, iPadOS, and macOS releases allows local users to run kernel code. BilerpGainTable::new_from_data performs unchecked 32-bit arithmetic on caller-controlled table dimensions and passes the wrapped size to kalloc_ext, underallocating storage for table data. The AppleCLCD method 78 path is reachable from an app sandbox without special entitlements, enabling kernel compromise; the public proof of concept causes a kernel panic.

The record

CVE
CVE-2021-30883
Published
Aug 24, 2021
Updated
Oct 21, 2025
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-787, T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2021CVE publishedPublication date reported by the CVE source.
  2. May 23, 2022Exploitation reportedCISA Known Exploited Vulnerabilities Catalog entry
  3. Oct 21, 2025Record 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 <14.8
  2. Affected versionversion=unspecified <15.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <14.8; version=unspecified <15.0
Apple · macOSversion=unspecified <11.6; version=unspecified <12.0; version=unspecified <15.1; version=unspecified <8.1

Published CVSS scores

9.3NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8CISA-ADPCVSS:3.1/AV:L/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.

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No observations available

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

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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