CVE-2021-30663
Apple Multiple Products: WebKit Integer Overflow
As of , CVE-2021-30663 in Apple Multiple Products is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch soon.
- Exploited
- Yes: CISA listed it on 3 November 2021
- US federal deadline
- 17 November 202114 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- EPSS score
- 0.04Higher than 88% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- EPSS when listed
- Not availableCISA listed it before 4 February 2022, where the EPSS files we read begin.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- No vendor link in CISA's entry
What CISA says to do
Apply updates per vendor instructions.
CISA's required action
What the flaw is
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.
CISA's 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.
The CVE record's description, from apple
- CVE published
- 8 September 2021
- Assigned by
- apple
- CVSS
- 7.8 High (CVSS 3.1, from CISA-ADP)
- CWE-190
- Integer Overflow or Wraparound
- CWE-20
- Improper Input Validation
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- no
- CISA SSVC, technical impact
- total
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Multiple Products: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2026-86950Out-of-Bounds Write | Apple Multiple Products | Patch nowForensic triage required by CISA; listed in the last 14 days | 0.01 | ||
| CVE-2021-30860Integer Overflow | Apple Multiple Products | Patch this weekEPSS 0.76 | 0.76 | ||
| CVE-2023-32434Integer Overflow | Apple Multiple Products | Patch this weekEPSS 0.52 | 0.52 | ||
| CVE-2019-8605Use-After-Free | Apple Multiple Products | Patch soonVerified Exploit-DB entry | 0.18 | ||
| CVE-2020-3837Memory Corruption | Apple Multiple Products | Patch soonVerified Exploit-DB entry | 0.15 | ||
| CVE-2019-8506Type Confusion | Apple Multiple Products | Patch soonVerified Exploit-DB entry | 0.16 | ||
| CVE-2023-28205WebKit Use-After-Free | Apple Multiple Products | Patch soon | 0.27 | ||
| CVE-2021-30807Memory Corruption | Apple Multiple Products | Patch soon | 0.29 | ||
| CVE-2025-31200Memory Corruption | Apple Multiple Products | Patch soon | 0.19 | ||
| CVE-2025-24085Use-After-Free | Apple Multiple Products | Patch soon | 0.18 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org