CVE-2021-1879

mediumpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.071 · 94 %ileEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV

Likely / severe?

7.08% (94th) EPSS

CVSS 4.3 · medium

Is it mine?

10 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

added 2021-11-03remediate by 2021-11-17

required action Apply updates per vendor instructions.

EPSS · scored 2026-10-27

Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability

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..

cvss

Technical severity, 0–10. One row per scoring source.

6.1

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 2.7

v3.16.1mediumAV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondary · ENISA EU

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondaryexploitability 2.8 · impact 2.7

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Hsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USprimaryCWE-79US

affected products (10)

Products and version ranges known to be affected.

Apple IOSunspecified → 12.5enisa_euvdEU
Apple iOS and iPadOSunspecified → 14.4enisa_euvdEU
Apple watchOSunspecified → 7.3enisa_euvdEU
Apple Inc. iOS≤ 12.5.2fstec_bduRU
Apple Inc. iPadOS≤ 14.4.2fstec_bduRU
Apple Inc. watchOS≤ 7.3.3fstec_bduRU
apple ipados< 14.4.2nvdUScpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
apple iphone os< 12.5.2nvdUScpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple iphone os13.0 → 14.4.2nvdUScpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple watchos< 7.3.3nvdUScpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-04-02modified 2026-06-17

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Related entries.

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+53003 more

references (14)

External citations — patches, advisories, analysis.

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