How severe is CVE-2021-30657?

CVE-2021-30657 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-30657?

Affected package information for CVE-2021-30657 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-30657?

No fixed release is recorded for CVE-2021-30657 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2021-30657 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2021-30657 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2021-30657 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2021-30657, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-30657?

CVE-2021-30657 has an EPSS (Exploit Prediction Scoring System) score of 68.5%, placing it in the 99th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-30657 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-30657 (Apple macOS Unspecified Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2021-11-17. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-30657?

CVE-2021-30657 is classified as CWE-862 (CWE-862). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-30657 published, and has it been updated?

CVE-2021-30657 was published on September 8, 2021 and was last updated on October 21, 2025. 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 · ACTIVELY EXPLOITED

MEDIUM severity

CVE-2021-30657

MEDIUM

CVE-2021-30657 is a medium-severity (CVSS 5.5) CWE-862 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. A malicious application may bypass Gatekeeper…

Published

Sep 8, 2021

Updated

Oct 21, 2025

Affected

2 products

Patched

See advisory

Exploits

5 known

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2021-11-17.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2021-30657.

EPSS Exploitation Probability

via FIRST.org ↗

68.5%probability of exploitation in next 30 days

High Risk-14.55%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-30657 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Counts from FIRST.org, log-scaled.

Description

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. A malicious application may bypass Gatekeeper checks. Apple is aware of a report that this issue may have been actively exploited..

Affected Products

2 products · 10 configurations

mac os xapple

≥ 10.15 && ≤ 10.15.5

2 versions

10.15.610.15.7

macosapple

≥ 11.0 && < 11.3

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

A logic issue was addressed with improved state management. This issue i…

github.comMetasploitAug 2021

A logic issue was addressed with improved state management. This issue i…

nvd.nist.govNVDSep 2021

A logic issue was addressed with improved state management. This issue i…

cisa.govCISANov 2021

A logic issue was addressed with improved state management. This issue i…

github.comGithubNov 2021

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2021-30657 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-30657 in your dependencies?

Find it across , including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.5/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Raw vector

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

CWE Classification

CWE-862CWE-862

Weaponization

No known public exploit tooling found.

Timeline

First exploit

Aug 27, 2021

Disclosed

Sep 8, 2021

KEV added

Nov 3, 2021

Last updated

Oct 21, 2025

Identifiers

CVE-2021-30657

References

Websupport.apple.com Websupport.apple.com Webcisa.gov

Related vulnerabilities

This CVE is medium severity; 6 of 8 other CVEs with CWE-862 are rated as high or higher (top: critical).

GHSA-7xgj-8392-5q4rCVE-2026-114135CVE-2026-113797CVE-2026-113649CVE-2026-114125CVE-2026-113648CVE-2026-112957CVE-2026-111767Browse all CWE-862

Provenance

Sources

OSV.devNVDCISA KEVFIRST.org (EPSS)

Last verifiedOct 21, 2025

CVE-2021-30657

Exploitation Status

Actively exploited in the wild

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

Frequently Asked Questions

Is CVE-2021-30657 in your dependencies?