CVE-2021-30687

Information disclosure via ImageIO out-of-bounds read

Published Sep 8, 2021 · Updated Aug 3, 2024

An out-of-bounds read in Apple ImageIO before iOS and iPadOS 14.6 and macOS Big Sur 11.4 allows attackers to disclose user information. ImageIO fails to enforce buffer bounds while decoding attacker-controlled image data, causing it to read beyond the intended buffer; Apple has not disclosed a narrower function or image format. Exploitation requires a crafted image to be processed and user interaction, and the documented consequence is limited to disclosure rather than modification or interruption.

CVSS severity5.5
Medium
EPSS probability1.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in Apple ImageIO before iOS and iPadOS 14.6 and macOS Big Sur 11.4 allows attackers to disclose user information. ImageIO fails to enforce buffer bounds while decoding attacker-controlled image data, causing it to read beyond the intended buffer; Apple has not disclosed a narrower function or image format. Exploitation requires a crafted image to be processed and user interaction, and the documented consequence is limited to disclosure rather than modification or interruption.

The record

CVE
CVE-2021-30687
Published
Sep 8, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-125, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 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 <14.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <14.6
Apple · macOSversion=unspecified <11.4; version=unspecified <14.6; version=unspecified <2021; version=unspecified <7.5

Published CVSS scores

4.3NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:N/A:N
5.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002Malicious File

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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