Exploited CVE from 2021, added in 2023

CVE-2021-30900

Apple iOS / iPadOS / macOS · Phones, tablets and chipsets

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

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on March 30, 2023.

Affected product: Apple iOS / iPadOS / macOS (category Phones, tablets and chipsets, indicative classification). Name in CISA’s catalog: Apple iOS, iPadOS, and macOS.

What should I do?

Apply the security update from Apple.

Deadline set by CISA for US federal agencies: 21 days (due April 20, 2023). It only binds those agencies, but it is a useful measure of urgency.

Apple security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2021-30900 on the NVD website.

Original text of the required action (CISA)

Apply updates per vendor instructions.

Timeline

August 24, 2021 Vulnerability published Publication date (NVD)
March 30, 2023 Exploitation confirmed Added to CISA’s KEV catalog
April 20, 2023 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on March 30, 2023 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the security update from Apple. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: April 20, 2023, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: August 24, 2021 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: Apple iOS, iPadOS, and macOS Filed by this site under “Phones, tablets and chipsets” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

7.8 / 10 CVSS severity: high

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

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.

Apple GPU drivers, included in iOS, iPadOS, and macOS, contain an out-of-bounds write vulnerability that may allow a malicious application to execute code with kernel privileges.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).