CVEs / CVE-2021-30663
CVE-2021-30663: Apple Multiple Products WebKit Integer Overflow Vulnerability
- Known exploited in the CISA KEV catalog since 3 Nov 2021
- high 8.8 CVSS 3.1 (NVD)
- EPSS 3.52% chance of exploitation in the next 30 days, higher than 89% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Apple iOS, iPadOS, macOS, tvOS, and Safari WebKit contain an integer overflow vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Description
An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Apple macOS | from unspecified, before 11.3 | 11.3 |
| Apple macOS | from unspecified, before 14.5 | 14.5 |
| Apple macOS | from unspecified, before 12.5 | 12.5 |
| Apple macOS | from unspecified, before 14.6 | 14.6 |
| Apple macOS | from unspecified, before 14.1 | 14.1 |
Exploitation
| In CISA KEV since | 3 Nov 2021 |
|---|---|
| Due date for US federal agencies | 17 Nov 2021 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 8.8 highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-190 |
References
- CVE-2021-30663 on NVD
- CVE-2021-30663 in the CISA KEV catalog
- CVE-2021-30663 on OSV
- https://support.apple.com/en-us/HT212335 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/HT212336 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/HT212341 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/HT212532 Release Notes, Vendor Advisory
- https://support.apple.com/en-us/HT212534 Release Notes, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30663 Third Party Advisory, US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.