CVE-2021-30666
ENISA EUVD: EUVD-2021-17583 ↗
Exploited in the Wild
✓ Confirmed 0-Day
Triaged: March 20, 2026
11 articles
Published: 2021-09-08
EPSS Score
Source: FIRST.org · 2026-05-23
1.18%
probability
This CVE has a 1.18% probability
of being exploited in the next 30 days.
0%
Top 79.0th percentile of all CVEs
100%
CVSS v3.1
Source: VulnerabilityLookup (CIRCL)8.8
HIGH
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v2 (legacy)
6.8
MEDIUM
Access Vector
Network
Access Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
Description
VulnerabilityLookup (CNA)A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
Affected Products
Apple
iOS
unspecified
Attack Intelligence
https://support.apple.com/en-us/HT212341
x_refsource_MISC
Signal Intelligence
Confidence
92%
EPSS
1.18%
CVSS v3.1
8.8
Mentions
11
Last Seen
Nov 09, 2021
CNA Information
CNA Assigner
apple
Analyst Note
Multiple authoritative sources (Qualys, BleepingComputer) explicitly identify CVE-2021-30666 as a zero-day exploited in the wild, with Apple issuing an emergency patch (iOS 15.0.2) to address active attacks. The exploitation preceded or coincided with patch availability, meeting zero-day criteria.
Triage Info
Decided atMar 20, 2026
Published DateSep 08, 2021