---
id: "CVE-2021-30657"
kind: "vulnerability"
aliases: ["CVE-2021-30657"]
title: "Apple macOS: Apple macOS Unspecified Vulnerability"
severity: "high"
cvss: 5.5
epss: 0.68531
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Apple macOS", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["apple-devices", "exploited", "infrastructure", "macos"]
not_affected_if: ["fully-patched-macos"]
published_at: "2021-09-08T15:15:13+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-30657", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2021-30657", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-30657", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Apple macOS: Apple macOS Unspecified Vulnerability

Apple macOS has a logic flaw in System Preferences that lets a malicious application bypass Gatekeeper checks. Attackers can run unsigned or untrusted software on a Mac that Gatekeeper would normally block.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Apple macOS affected ? fixed ?

## Fix

Apply the macOS updates from Apple per CISA's required action; the sources do not name the exact fixed version.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-30657
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2021-30657
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2021-30657

## From the sources

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..

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_