Is CVE-2020-27930 (Apple Multiple Products Memory Corruption) being exploited in the wild?

Yes. CISA added CVE-2020-27930 to its Known Exploited Vulnerabilities catalogue on 3 November 2021, which it does only when there is reliable evidence of active exploitation. CISA has not linked it to known ransomware campaigns. Apple iOS, iPadOS, macOS, and watchOS FontParser contain a memory corruption vulnerability which may allow for code execution when processing maliciously crafted front.

What “exploited in the wild” means for this CVE

For a CVE question like this, the key issue is not whether the flaw exists, but whether reliable evidence shows active exploitation. CISA’s KEV catalogue is the practical signal that matters most for that judgment, because inclusion means CISA has judged the vulnerability to be exploited and worth urgent attention.

When a memory corruption flaw reaches that stage, the operational question shifts from normal patch planning to exposure control. You should treat the affected Apple product line as potentially targeted until you have confirmed version status, exposure to the vulnerable component, and whether any devices were reachable during the exploitation window.

How to confirm exposure and respond safely

Start by identifying where Apple iOS, iPadOS, macOS, or watchOS systems are in scope and whether they are still running vulnerable builds. For an exploited flaw, patch verification matters as much as patch deployment, because a device that was missed, delayed, or exempted remains a live risk even after the headline advisory has aged out.

CISA Known Exploited Vulnerabilities Catalog is the best source for the current KEV record, while the CVE Program and NIST National Vulnerability Database help you align the record to the underlying vulnerability entry and product context.

If patching must wait, reduce exposure immediately by removing the affected systems from risky network paths, limiting untrusted content handling, and tightening who can interact with user-facing input surfaces that process files or media. For a memory corruption issue, the goal is to make exploitation harder and to narrow the blast radius while you complete remediation.

What to check after patching

Because the direct answer indicates active exploitation, remediation should include a compromise review, not just installation of the fix. Review device telemetry, authentication anomalies, unexpected crashes, suspicious process behavior, and any signs that malicious content was processed before the fix was applied.

If the devices handled sensitive data, were used for privileged access, or were exposed to external content channels, consider whether sessions, tokens, or related credentials may need review or rotation. That step is not automatic for every CVE, but it becomes material when the affected endpoint could have been used as a foothold or content-processing entry point.

Risk and Threat Considerations

Actively exploited client and platform vulnerabilities are attractive because they can turn normal user interaction into code execution without requiring obvious misuse. Memory corruption in a parser or similar component can create a high-value attack path when the vulnerable software processes attacker-controlled content.

Failure mechanism: Maliciously crafted input triggers unsafe memory handling in the vulnerable parser, which can let an attacker execute code or chain into broader device compromise.

Impact: A successful exploit can expose data, enable persistence, or provide a foothold for lateral movement, especially if the affected device has access to accounts, services, or trusted networks.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

NIST CSF 2.0, CIS Controls v8 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
NIST CSF 2.0	ID.RA-01 — Asset Vulnerabilities Are Identified and Documented	The question is about a known exploited vulnerability and exposure confirmation.
	PR.DS-01 — Data-at-rest is protected	Exploitation can expose stored data on affected devices and accounts.
Recommendation — Document affected Apple systems and track their exposure to the KEV-listed flaw. Protect sensitive data on devices that may have been compromised.
CIS Controls v8	CIS-7 — Continuous Vulnerability Management	Active exploitation makes rapid identification, prioritisation and remediation the core control problem.
Recommendation — Prioritise KEV-listed systems for rapid remediation and verification.
NIST SP 800-53 Rev 5	RA-5 — Vulnerability Monitoring and Scanning	This CVE requires confirmation of exposure and ongoing vulnerability visibility.
	SI-2 — Flaw Remediation	The answer centers on fixing an exploited vulnerability and validating closure.
Recommendation — Scan for affected Apple systems and verify remediation status. Apply the vendor fix quickly and confirm the flaw is remediated.

Practitioner Guidance

What to verify: Confirm both patch status and exposure path. For exploited vulnerabilities, “installed somewhere in the estate” is not enough, you need to know which devices parsed untrusted content before remediation and whether they were used for sensitive access.

Decision rule: If the device is internet-facing, handles external content, or supports privileged work, prioritize it ahead of lower-value endpoints even when the CVE is already months old. If you cannot patch immediately, isolate the device and reduce content-processing exposure first.

Practitioner takeaway: For a KEV-listed flaw, the right question is not “is it patched yet?” but “where could exploitation still have occurred, and what evidence do we have that the device remained trustworthy afterward?”