Security readout for executives and security teams
Plain-English summary
CVE-2020-27919 is an Apple macOS flaw where opening or processing a malicious image could let code run on the affected Mac. Apple fixed it through macOS Big Sur releases and Catalina/Mojave security updates. The sources do not say it was exploited in the wild.
Executive priority
Treat this as a high-priority legacy macOS remediation item if older Macs remain in service. Business urgency is highest where users receive external images or where patch compliance for Catalina, Mojave, or early Big Sur is uncertain.
Technical view
Apple describes an out-of-bounds write corrected with improved input validation. The documented impact is arbitrary code execution when a maliciously crafted image is processed. The source bundle does not identify the exact component, CVSS score, CWE, exploitability details, or affected build ranges beyond macOS updates.
Likely exposure
Exposure is most likely on Macs that did not receive macOS Big Sur 11.0.1 or 11.1, Security Update 2020-001 Catalina, or Security Update 2020-007 Mojave. Systems that process untrusted images are the relevant risk surface.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not marked as CISA KEV. Exploitation requires a maliciously crafted image to be processed, but the bundle does not provide attack-chain details or public exploit evidence.
Researcher notes
The public record is sparse. It confirms an out-of-bounds write, image-processing trigger, arbitrary-code-execution impact, and Apple fixed versions. It does not name the vulnerable component, vulnerable version boundaries, exploit prerequisites, privileges, sandbox impact, or indicators of compromise.
Mitigation direction
- Update macOS to Apple’s fixed versions or later.
- Apply Security Update 2020-001 Catalina where Catalina remains in use.
- Apply Security Update 2020-007 Mojave where Mojave remains in use.
- Check Apple advisories for any environment-specific guidance.
- Prioritize legacy Macs that handle external image files.
Validation and detection
- Inventory macOS versions across managed endpoints.
- Confirm fixed update levels are installed on Catalina, Mojave, and Big Sur systems.
- Review vulnerability scanner findings against Apple advisory references.
- Identify business workflows that process untrusted images.
- Track exceptions for unsupported or unpatchable Macs.
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-2020-27919 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.