CVE-2021-30858

Advisory lineage Upstream: 0 Downstream: 20
Analyzed
Published: 24 Aug 2021, 18:49
Last modified:21 Oct 2025, 23:25

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.8 HIGH
v3.1 (cve.org)
EPSS Score
0.79% LOW
1% probability 0.00%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Aug 2021, 18:49
Published
Vulnerability first disclosed
03 Nov 2021, 00:00
Added to CISA KEV
Apple iOS, iPadOS, macOS Use-After-Free Vulnerability
17 Nov 2021, 00:00
CISA Remediation Due
Apply updates per vendor instructions.
21 Oct 2025, 23:25
Last Modified
Vulnerability information updated

Description

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6. 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.

CVSS Metrics

  • v3.1•HIGH•Score: 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
  • v2.0•MEDIUM•Score: 6.8AV:N/AC:M/Au:N/C:P/I:P/A:P

EPSS Trends

Current EPSS score: 0.79%• Percentile: 74%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • Unknown•iOS

    ≥ unspecified, < 14.8

  • apple•ipados

    ≥ 13.1, < 14.8

  • apple•iphone_os

    < 12.5.5 | ≥ 13.0, < 14.8

  • Unknown•macOS

    < 11.6 | ≥ unspecified, < 11.6

  • debian•debian_linux

    10.0 | 11.0

  • fedoraproject•fedora

    33 | 34

References (19)