CVE-2021-30776

Application crash via insufficient audio validation

Published Sep 8, 2021 · Updated Aug 3, 2024

A CoreAudio logic error in Apple iOS before 14.7, macOS Big Sur before 11.5, and Catalina allows attackers to crash audio apps. Apple states only that CoreAudio applies insufficient validation when playing a malicious audio file and has not disclosed the rejected field or state. Exploitation requires a user or application to play the crafted file; the documented consequence is application termination, not system compromise.

CVSS severity5.5
Medium
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A CoreAudio logic error in Apple iOS before 14.7, macOS Big Sur before 11.5, and Catalina allows attackers to crash audio apps. Apple states only that CoreAudio applies insufficient validation when playing a malicious audio file and has not disclosed the rejected field or state. Exploitation requires a user or application to play the crafted file; the documented consequence is application termination, not system compromise.

The record

CVE
CVE-2021-30776
Published
Sep 8, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
iOS
Classifications
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 <14.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOSversion=unspecified <14.7
Apple · Security Update Catalinaversion=unspecified <2021
Apple · macOSversion=unspecified <11.5; version=unspecified <14.7; version=unspecified <7.6

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NVDAV:N/AC:M/Au:N/C:N/I:N/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.

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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 exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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