How to check if you are exposed to CVE-2021-30663
- Find every Apple Multiple Products system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
- Compare each version with the fixed versions in the vendor advisory. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
- Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2021-30663.
US federal agencies had to fix this by 2021-11-17. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.
Affected versions
Versions the National Vulnerability Database lists as vulnerable to CVE-2021-30663. Check the vendor advisory for the exact fixed builds before you sign anything off.
| Product | Vulnerable versions |
|---|---|
| Apple Safari | before 14.1.1 |
| Apple Ipados | from 14.0 before 14.5.1 |
| Apple Iphone OS | before 12.5.3; from 14.0 before 14.5.1 |
| Apple Macos | from 11.0 before 11.3.1 |
| Apple Tvos | before 14.6 |
Timeline
- · Published in the National Vulnerability Database
- · Added to CISA's Known Exploited Vulnerabilities catalog, 56 days after it was published
- · Fix-by date for US federal agencies, passed 1,810 days ago
Weakness type
More exploited Apple vulnerabilities
CISA lists 95 exploited Apple vulnerabilities. The closest matches:
- CVE-2026-86950Apple Multiple Products Out-of-Bounds Write VulnerabilityAdded 2026-09-29
- CVE-2025-43520Apple Multiple Products Classic Buffer Overflow VulnerabilityAdded 2026-03-20
- CVE-2025-43510Apple Multiple Products Improper Locking VulnerabilityAdded 2026-03-20
- CVE-2025-31277Apple Multiple Products Buffer Overflow VulnerabilityAdded 2026-03-20
- CVE-2023-43000Apple Multiple products Use-After-Free VulnerabilityAdded 2026-03-05
- CVE-2021-30952Apple Multiple Products Integer Overflow or Wraparound VulnerabilityAdded 2026-03-05
- CVE-2026-20700Apple Multiple Buffer Overflow VulnerabilityAdded 2026-02-12
- CVE-2025-43529Apple Multiple Products Use-After-Free WebKit VulnerabilityAdded 2025-12-15
Keep going
Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.