What is CVE-2021-30952?
An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.
The record classifies CVE-2021-30952 under weakness class CWE-190. Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 12 affected-product entries are recorded, across 5 vendors, listed below. The identifier was first published 1895 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.8 — HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 6.9% probability of exploitation in the next 30 days, higher than 93.9% of all scored CVEs
- CISA KEV
- Listed since 2026-03-05, federal remediation deadline 2026-03-26
- Threadlinqs priority
- 9/10 — CISA KEV-listed, which Threadlinqs floors at 9
- Published
- 2021-08-24, last modified 2026-03-06
Is CVE-2021-30952 being exploited?
CISA added CVE-2021-30952 to the Known Exploited Vulnerabilities catalog on 2026-03-05, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-03-26 under BOD 22-01. Weaponised exploit code for CVE-2021-30952 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 56 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
- Apple: Safari, Ipados, Iphone Os, Macos, Tvos, Watchos
- Fedoraproject: Fedora 34, Fedora 35
- Debian: Linux 10.0, Linux 11.0
- Webkitgtk: Webkitgtk
- Wpewebkit: Wpe Webkit
How to fix CVE-2021-30952
The record marks a vendor fix as available for CVE-2021-30952. Patch reference: https://support.apple.com/en-us/HT212976. Vendor advisory: https://support.apple.com/en-us/HT212975. Because CVE-2021-30952 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-03-26. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2021-30952
4 tracked threats in the Threadlinqs corpus reference CVE-2021-30952, either in the campaign’s CVE list or as an indicator on the campaign record.
- DeadTag campaign: Coruna and DarkSword iPhone exploit kits delivered via expired ad/analytics tags, compromised websites and malicious ads — HIGH · 2026-10-27
- Coruna and DarkSword iOS Exploit Kits Compromise iPhones via Single Malicious Website (UNC6353, UNC6691, UNC6748, PARS Defense) — HIGH · 2026-10-14
- Coruna iOS Exploit Kit — 23 Exploits Across 5 Chains Targeting iOS 13-17.2.1 (CVE-2021-30952, CVE-2023-41974, CVE-2023-43000 + 20 More) — CRITICAL · 2026-03-06
- Coruna iOS Exploit Kit — Government-Grade 23-Exploit Arsenal Proliferates from Surveillance Vendor to Russian Espionage and Chinese Cybercriminals Targeting 42K+ Devices — CRITICAL · 2026-03-04
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, public proof-of-concept repositories. Last verified by Threadlinqs on .
Vendor advisory and patch
- lists.fedoraproject.org — vendor advisory
- debian.org — vendor advisory
- debian.org — vendor advisory (dsa 5060)
- lists.fedoraproject.org — vendor advisory (HQKWD4BXRDD2YGR5AVU7H5J5PIQIEU6V)