CVE-2021-1871A logic issue was addressed with improved restrictions.
Updated under an hour ago ()
Does this affect you?
It affects Apple iOS and iPadOS and 6 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021. Treat that date as your deadline.
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A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
- CVSS
- 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021Apply updates per vendor instructions.
- EPSS (exploitation in the next 30 days)
- 7.00% (percentile 94)
- Assigned by
- apple
- NVD analysis
- Analyzed
- Record last updated
- Oct 21, 2025
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Apple iOS and iPadOS apple:ios_and_ipados (from the name) | from unspecified before 14.4 | CNA record |
Apple macOS apple:macos (from the name) | from unspecified before 11.2 | CNA record |
apple ipados apple:ipados | before 14.4 | NVD |
apple iphone_os apple:iphone_os | before 14.4 | NVD |
apple mac_os_x apple:mac_os_x | from 10.15 before 10.15.7; 10.15.7; 10.15.7; 10.15.7 | NVD |
apple macos apple:macos | from 11.0.1 before 11.2 | NVD |
debian debian_linux debian:debian_linux | 10.0 | NVD |
fedoraproject fedora fedoraproject:fedora | 33 | NVD |
References
- https://support.apple.com/en-us/HT212147x-refsource-misc, release-notes, vendor-advisory
- https://support.apple.com/en-us/HT212146x-refsource-misc, release-notes, vendor-advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/vendor-advisory, x-refsource-fedora, broken-link, mailing-list
- https://www.debian.org/security/2021/dsa-4923vendor-advisory, x-refsource-debian, mailing-list, third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1871us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.