CVE-2021-30663: Apple Multiple Products WebKit Integer Overflow Vulnerability

Vulnerability summary

CVE-2021-30663 is a high (CVSS 8.8) Integer Overflow or Wraparound vulnerability in Apple Multiple Products. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 3.52% chance of exploitation in the next 30 days, higher than 89% of scored vulnerabilities.

Timeline

1. 08-09-2021
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVApple Multiple Products WebKit Integer Overflow Vulnerability
3. 17-11-2021
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.