CVE-2021-1879

ENISA EUVD: EUVD-2021-7343 ↗
Exploited in the Wild ✓ Confirmed 0-Day ★ Google Project Zero
Triaged: March 3, 2026 15 articles Published: 2021-04-02
VulnLookup ↗ NVD ↗ EUVD ↗ MITRE ↗ Advisory ↗ P0 Sheet ↗ CISA KEV ↗

EPSS Score

Source: FIRST.org · 2026-05-23
0.81%
probability
This CVE has a 0.81% probability of being exploited in the next 30 days.
0% Top 74.4th percentile of all CVEs 100%

CVSS v3.1

Source: VulnerabilityLookup (CIRCL)
6.1
MEDIUM
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS v2 (legacy)

4.3
MEDIUM
Access Vector
Network
Access Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
AV:N/AC:M/Au:N/C:N/I:P/A:N

Description

VulnerabilityLookup (CNA)
This issue was addressed by improved management of object lifetimes. This issue is fixed in iOS 12.5.2, iOS 14.4.2 and iPadOS 14.4.2, watchOS 7.3.3. Processing maliciously crafted web content may lead to universal cross site scripting. Apple is aware of a report that this issue may have been actively exploited..

Affected Products

Apple
iOS and iPadOS
unspecified
Apple
iOS
unspecified
Apple
watchOS
unspecified

Google Project Zero

Patched
March 26, 2021
Reported by
Clement Lecigne of Google Threat Analysis Group and Billy Leonard of Google Threat Analysis Group
Root Cause Analysis
https://googleprojectzero.github.io/0days-in-the-wild//0day-RCAs/2021/CVE-2021-1879.html

Signal Intelligence

Confidenceⓘ
92%
EPSS 0.81%
CVSS v3.1 6.1
Mentions 15
Last Seen Aug 29, 2024

CNA Information

CNA Assigner
apple

Analyst Note

CVE-2021-1879 demonstrates strong confirmation signals including Apple's explicit acknowledgment of active exploitation, Google Project Zero inclusion, and documented real-world use by APT29. The vulnerability affects widely-deployed iOS/iPadOS platforms with fixed patches available, and the UXSS impact on web content processing represents a credible threat vector.

Threat Actors 2

Kinsing
apt_group 🇷🇺 RU
TeamTNT
apt_group 🇩🇪 DE

Triage Info

Decided atMar 03, 2026
Published DateApr 02, 2021