An integer overflow was addressed with improved input validation.
Affects Apple macOS releases before 11.3, 12.5, 14.1, 14.5 and 14.6, with fixes listed for each release line. CVSS rates it 7.8 (high), and no separate vendor rating is given. Apple's fixes are the update path.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Actively exploited
- Fix
- Fixed in 11.3, 14.5, 12.5, 14.6, 14.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
This vulnerability affects Apple's iOS, iPadOS, tvOS, Safari, and macOS Big Sur operating systems and browser. Processing maliciously crafted web content could allow an attacker to execute arbitrary code on the affected device.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
Affected versions
- Apple macOS
From unspecified · fixed in 11.3
- Apple macOS
From unspecified · fixed in 14.5
- Apple macOS
From unspecified · fixed in 12.5
- Apple macOS
From unspecified · fixed in 14.6
- Apple macOS
From unspecified · fixed in 14.1
References 5
Questions about CVE-2021-30663
What does this mean?
An integer overflow happens when a number grows beyond the largest value the code can store, which can corrupt memory handling. Apple fixed it with improved input validation. The impact quote says processing maliciously crafted web content may lead to arbitrary code execution.Source: support.apple.com
Am I affected, and how do I check?
The checked facts list macOS releases fixed in 11.3, 12.5, 14.1, 14.5 and 14.6, with no earlier introduced version given. To check a Mac, open the Apple menu, choose About This Mac, and compare the macOS version with those fixed releases.Source: support.apple.com
What should I do about it?
Update macOS to the fixed release for its release line: 11.3, 12.5, 14.1, 14.5 or 14.6, or a later release. The checked facts also list iOS 12.5.3 as a fixed version for iOS, which is a separate product.Source: support.apple.com
Is it being exploited?
Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means it has evidence of attacks. No public exploit code is tracked.Source: cisa.gov, cve.now feed data