Security readout for executives and security teams
Plain-English summary
This Apple macOS issue can be triggered when a malicious AppleScript binary is processed. The documented outcomes are application termination or possible disclosure of process memory. Apple fixed it in Monterey 12.0.1, Big Sur 11.6.1, and Security Update 2021-007 for Catalina.
Executive priority
Treat this as a routine but important macOS patching item. It has confidentiality and availability impact, but the provided evidence does not show active exploitation or a critical remote-wormable condition.
Technical view
CVE-2021-30877 is an out-of-bounds read in macOS AppleScript binary processing. Apple states it was addressed through improved bounds checking. The source bundle does not provide CVSS, CWE, detailed vulnerable version ranges, or component internals beyond affected macOS releases.
Likely exposure
Exposure is most likely on macOS systems older than Monterey 12.0.1, Big Sur 11.6.1, or Catalina without Security Update 2021-007 that process untrusted AppleScript binaries.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not marked in CISA KEV. The known attacker requirement is getting a maliciously crafted AppleScript binary processed by the target system.
Researcher notes
Public detail is limited. Apple names the bug class, trigger, impact, and fixed releases, but does not identify CVSS, CWE, vulnerable build ranges, exploit maturity, or deeper root-cause specifics in the supplied sources.
Mitigation direction
- Update Monterey systems to macOS Monterey 12.0.1 or later.
- Update Big Sur systems to macOS Big Sur 11.6.1 or later.
- Apply Security Update 2021-007 on Catalina systems.
- Consult Apple guidance for any unsupported or successor macOS handling.
- Reduce user exposure to untrusted AppleScript binaries where feasible.
Validation and detection
- Inventory macOS versions across managed endpoints.
- Confirm Catalina hosts have Security Update 2021-007 installed.
- Confirm Big Sur hosts are at 11.6.1 or later.
- Confirm Monterey hosts are at 12.0.1 or later.
- Review endpoint controls for handling untrusted AppleScript binaries.
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.
CVE-2021-30877 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/HT212869CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212871CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212872CVE 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.