How severe is CVE-2021-30952?

CVE-2021-30952 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-30952?

Affected package information for CVE-2021-30952 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-30952?

No fixed version has been published for CVE-2021-30952 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-30952 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-30952 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-30952?

CVE-2021-30952 has an EPSS (Exploit Prediction Scoring System) score of 0.8%, placing it in the 74th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2021-30952 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-30952 (Apple Multiple Products Integer Overflow or Wraparound Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-03-05. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-03-26. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2021-30952 published, and has it been updated?

CVE-2021-30952 was published on August 24, 2021 and was last updated on April 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2026-03-05 — agencies required to remediate by 2026-03-26

CVE-2021-30952

HIGH

Published

Aug 24, 2021

Updated

Apr 16, 2026

Affected

0 pkgs

Patched

None yet

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.8%probability of exploitation in next 30 days

Lower Risk74th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-30952 in your stack?

O3 detects CVE-2021-30952 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works

CVSS Score

7.8/10

CVSS v3 base score

Vector breakdown

AV:Attack Vector

Local

AC:Attack Complexity

Low

PR:Privileges Required

None

UI:User Interaction

Required

S:Scope

Unchanged

C:Confidentiality

High

I:Integrity

High

A:Availability

High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Aug 24, 2021

KEV added

Mar 5, 2026

Last updated

Apr 16, 2026

Identifiers

CVE-2021-30952

References

Advisoryopenwall.com Advisorysupport.apple.com Advisorysupport.apple.com Advisorydebian.org Advisorysupport.apple.com Advisorysupport.apple.com Advisorysupport.apple.com Advisorydebian.org Weblists.fedoraproject.org Weblists.fedoraproject.org Webcisa.gov Evidencecloud.google.com

Data from OSV.dev, enriched by O3 Security. Refreshed hourly.