Security readout for executives and security teams
Plain-English summary
CVE-2021-30856 is a macOS privacy bypass tied to Remote Login. If Remote Login is enabled, a malicious unsandboxed app may bypass macOS Privacy preferences. Apple says it addressed the issue in macOS Big Sur 11.3 by adding a Remote Login option for Full Disk Access for Secure Shell sessions.
Executive priority
Prioritize managed Macs that permit Remote Login, especially administrator or developer workstations. Business urgency is moderate because the issue can weaken privacy controls, but current source evidence does not show active exploitation.
Technical view
The disclosed condition affects Apple macOS systems with Remote Login enabled. The vulnerability allows a malicious unsandboxed app to bypass Privacy preferences. Apple’s stated fix is in macOS Big Sur 11.3 and changes Remote Login behavior by making Full Disk Access for Secure Shell sessions opt-in.
Likely exposure
Exposure is most likely on macOS systems where Remote Login is enabled and the system has not received Apple’s macOS Big Sur 11.3 fix. The source bundle does not identify broader product versions or affected build ranges.
Exploitation context
The provided sources do not indicate active exploitation, and the CVE is not listed as KEV in the bundle. The described attacker condition is a malicious unsandboxed app on a system with Remote Login enabled.
Researcher notes
Evidence is limited to Apple’s advisory and CVE metadata. No CVSS, CWE, exploit details, or complete affected version matrix are provided in the bundle. Treat Remote Login state and macOS 11.3 remediation status as the main validation pivots.
Mitigation direction
- Update affected macOS systems to macOS Big Sur 11.3, per Apple guidance.
- Disable Remote Login where it is not operationally required.
- Review Remote Login Full Disk Access configuration after updating.
- Monitor Apple guidance for any additional version-specific instructions.
Validation and detection
- Inventory macOS systems and identify those with Remote Login enabled.
- Confirm whether each exposed system has macOS Big Sur 11.3 applied.
- Review Privacy and Full Disk Access settings for Secure Shell sessions.
- Check endpoint telemetry for suspicious unsandboxed applications on exposed systems.
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
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CVE-2021-30856 mapping review
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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/HT212325CVE 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.