Exploited vulnerability · CISA KEV

Is CVE-2021-30657 exploited? Yes: in CISA KEV since 3 Nov 2021

Gociux · Apple macOS · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-30657, Apple macOS Unspecified Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 3 Nov 2021, 56 days after it was published. It affects Apple macOS. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 3 Nov 2021

ransomwareNot knownno confirmed use

EPSStop 1%among the most likely CVEs to be exploited

severity5.5CVSS 3.1 · medium

US federal due17 Nov 2021BOD 22-01 deadline

What it is

Apple macOS contains an unspecified logic issue in System Preferences that may allow a malicious application to bypass Gatekeeper checks.

Vendor	Apple (96 exploited CVEs in KEV)
Product	macOS
Vulnerability	Apple macOS Unspecified Vulnerability
Weakness	CWE-862
Published	8 Sep 2021
Added to KEV	3 Nov 2021
Reported by (CNA)	apple

What to do

Check whether you run it. Look for macOS in your asset inventory, including appliances and cloud images. Stack check lists every exploited Apple CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 8 Sep 2021.
Get told next time. Email alerts when CISA adds a CVE for Apple.

Other exploited CVEs in macOS

CVE-2026-65400: Apple macOS Improper Authentication Vulnerability (18 Aug 2026)
CVE-2019-8526: Apple macOS Use-After-Free Vulnerability (17 Apr 2023)
CVE-2022-22675: Apple macOS Out-of-Bounds Write Vulnerability (4 Apr 2022)
CVE-2022-22674: Apple macOS Out-of-Bounds Read Vulnerability (4 Apr 2022)
CVE-2021-30713: Apple macOS Unspecified Vulnerability (3 Nov 2021)

References

nvd.nist.gov/vuln/detail/CVE-2021-30657

Questions

Is CVE-2021-30657 being exploited?

Yes. CISA added CVE-2021-30657 to the Known Exploited Vulnerabilities catalog on 3 Nov 2021, which means there is reliable evidence of exploitation in the wild.

Is CVE-2021-30657 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2021-30657?

Apply updates per vendor instructions. Check Apple's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected macOS and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in November 2021 · Apple scorecard · act-now radar.

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