PatchSiren cyber security CVE debrief
CVE-2021-30858 Apple CVE debrief
CVE-2021-30858 is a use-after-free vulnerability affecting Apple iOS, iPadOS, and macOS. CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03, indicating it has been observed in active exploitation. Apple users and administrators should treat this as a high-priority remediation item and apply vendor updates as soon as possible.
- Vendor
- Apple
- Product
- iOS, iPadOS, and macOS
- CVSS
- Unknown
- CISA KEV
- Listed
- Original CVE published
- 2021-11-03
- Original CVE updated
- 2021-11-03
- Advisory published
- 2021-11-03
- Advisory updated
- 2021-11-03
Who should care
Apple device users, enterprise macOS/iOS/iPadOS administrators, endpoint/security teams, and organizations that rely on Apple-managed fleets or mobile device management.
Technical summary
The supplied sources identify the issue as a use-after-free vulnerability in Apple iOS, iPadOS, and macOS. No additional technical details, affected component names, or exploitation conditions are provided in the source corpus. The most important operational signal is its inclusion in CISA's KEV catalog and the associated instruction to apply updates per vendor guidance.
Defensive priority
Very high. KEV inclusion means defenders should prioritize remediation over routine patch queues, especially on broadly deployed Apple endpoints.
Recommended defensive actions
- Apply Apple vendor updates that address CVE-2021-30858 as soon as possible.
- Check Apple device management and inventory data to identify exposed iPhone, iPad, and Mac systems.
- Verify patch compliance across managed fleets and escalate any exceptions.
- Monitor CISA KEV and Apple advisories for any follow-on guidance or related updates.
- Treat unpatched systems as elevated risk until remediation is confirmed.
Evidence notes
The debrief is based on the supplied CVE metadata and CISA KEV source item only. The corpus confirms the vulnerability class (use-after-free), the affected vendor/product families (Apple iOS, iPadOS, and macOS), the CVE publication date (2021-11-03), and KEV status with a due date of 2021-11-17. No CVSS score, exploit chain details, or component-level technical root cause were provided.
Official resources
-
CVE-2021-30858 CVE record
CVE.org
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CVE-2021-30858 NVD detail
NVD
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CISA Known Exploited Vulnerabilities catalog
CISA - Apply updates per vendor instructions.
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Source item URL
cisa_kev
Public debrief derived from official CVE/CISA source records supplied in the corpus. No exploit instructions or non-public details included.