Security readout for executives and security teams
Plain-English summary
CVE-2020-27921 is an Apple macOS kernel-level issue caused by a race condition. Apple states an application may be able to execute arbitrary code with kernel privileges. That makes the business risk significant on unpatched Macs, because kernel privileges can undermine normal operating system controls.
Executive priority
Treat this as a high-priority endpoint patching issue for legacy macOS fleets. The direct business concern is local application-to-kernel compromise on unpatched Macs, but the available sources do not show active exploitation.
Technical view
The CVE describes a race condition in macOS that Apple addressed with improved state handling. The reported impact is arbitrary code execution with kernel privileges by an application. The affected macOS versions are not specifically enumerated beyond Apple’s fixed releases and security updates.
Likely exposure
Exposure is most likely on macOS systems that have not received macOS Big Sur 11.0.1 or 11.1, Security Update 2020-001 Catalina, or Security Update 2020-007 Mojave. The source bundle does not define precise vulnerable version ranges.
Exploitation context
The source bundle does not report active exploitation, and this CVE is not marked as CISA KEV. The stated attack context is an application executing arbitrary code with kernel privileges, but the sources do not provide exploit maturity or public exploit evidence.
Researcher notes
Apple attributes the fix to improved state handling for a race condition. Public details in the provided sources are sparse: no CVSS, CWE, exact vulnerable version range, exploit status, or technical root-cause detail is included.
Mitigation direction
- Apply the Apple macOS release or security update listed for the affected operating system.
- Use vendor guidance for any currently supported macOS upgrade path.
- Prioritize Macs that run untrusted software or support privileged business workflows.
- Retire, upgrade, or isolate macOS versions that cannot receive the listed security updates.
Validation and detection
- Inventory macOS versions across managed and unmanaged endpoints.
- Confirm each host has the relevant Big Sur, Catalina, or Mojave security update installed.
- Check endpoint management reports for failed or deferred macOS update deployments.
- Review exception lists for Macs intentionally held below fixed versions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Execution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-27921 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://support.apple.com/en-us/HT211931CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212011CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.