Security readout for executives and security teams
Plain-English summary
A malicious or compromised app on affected Apple systems could bypass file restrictions by abusing symlink handling and read files it should not access. Apple fixed the issue in 2021 security updates. Treat this as a privacy and local data exposure risk, especially on unmanaged or legacy Apple devices.
Executive priority
Handle through normal but time-bound Apple patch governance. Escalate priority for devices used by executives, administrators, developers, or staff handling sensitive files, because the documented impact is restricted-file access by an application.
Technical view
CVE-2021-30855 is an Apple symlink validation flaw. Apple says an application may be able to access restricted files. The issue was addressed with improved symlink validation. The provided sources do not include CVSS, CWE, vulnerable version ranges, attack prerequisites, or root-cause detail beyond symlink handling.
Likely exposure
Exposure is most likely on Apple devices missing the named 2021 fixes: Security Update 2021-005 Catalina, macOS Big Sur 11.6, iOS/iPadOS 14.8 or 15, and watchOS 8. The bundled affected-product list only names macOS, while Apple’s fixed-version text also references iOS, iPadOS, and watchOS.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The described condition requires an application able to trigger the vulnerable symlink handling path. Public sources provided do not confirm remote exploitability, chaining, or weaponized exploitation.
Researcher notes
Evidence is limited to Apple’s advisory language and CVE metadata. Useful validation is version and patch-state confirmation, not exploit reproduction. Avoid assuming sandbox escape, privilege escalation, or active exploitation unless additional vendor or KEV evidence is obtained.
Mitigation direction
- Install Apple’s fixed updates named in the source bundle.
- Prioritize unmanaged, legacy, and BYOD Apple devices for update checks.
- Review Apple support pages for any later vendor guidance.
- Restrict untrusted applications on devices pending remediation.
Validation and detection
- Inventory macOS, iOS, iPadOS, and watchOS versions against Apple fixed releases.
- Confirm Catalina systems have Security Update 2021-005 installed.
- Check endpoint management reports for devices below fixed versions.
- Review application control alerts for untrusted local apps.
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-2021-30855 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/HT212804CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212805CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212807CVE reference · x_refsource_MISC
- https://support.apple.com/kb/HT212815CVE reference · x_refsource_CONFIRM
- https://support.apple.com/en-us/HT212814CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212819CVE 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.