Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability

HIGH 7.8EXPLOITED (CISA KEV)CVE-2021-30900 · Published 24/08/2021 · updated 17/06/2026

Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability. Actively exploited: CISA added this vulnerability to its Known Exploited Vulnerabilities catalog on 30/03/2023. Patch affected systems as an emergency.

In short

CVE-2021-30900 is a HIGH (CVSS 7.8) vulnerability.
Exploited in the wild: CISA added it to the KEV catalog on 30/03/2023.
Chance of exploitation in the next 30 days (EPSS): 5.2%, higher than 92.5% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
iOS, iPadOS, and macOS Apple	Versions not published yet (product named by CISA KEV)

Description

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.

References

support.apple.com/en-us/HT212867 · Vendor Advisory
support.apple.com/en-us/HT212868 · Vendor Advisory
support.apple.com/kb/HT212872 · Vendor Advisory
cisa.gov/known-exploited-vulnerabilities-catalog · US Government Resource
CISA KEV · CVE-2021-30900

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