CVE-2021-30817
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur...
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.5. A malicious application may be able to access data about the accounts the user is using Family Sharing with.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.5. A malicious application may be able to access data about the accounts the user is using Family Sharing with.
- Record
CVE-2021-30817- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
CVE List No score
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.5. A malicious application may be able to access data about the accounts the user is using Family Sharing with.
- Record
CVE-2021-30817- Updated
- 2026-11-02
EUVDEUVD-2021-17734 No score
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.5. A malicious application may be able to access data about the accounts the user is using Family Sharing with.
- Record
EUVD-2021-17734- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-363f-7q84-2cr6 No score
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur...
A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.5. A malicious application may be able to access data about the accounts the user is using Family Sharing with.
- Record
GHSA-363f-7q84-2cr6- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-30817 is a medium vulnerability (CVSS 5.5) in Apple Macos, published October 28, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.63%, the 50th percentile. No source names a fixed version.