# CVE-2021-1879: Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability

> CVE-2021-1879: Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability. CVSS 6.1 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2021-1879
Last updated: 2025-10-21T23:25:49Z

- Published: 2021-04-02 18:07 UTC · Updated: 2025-10-21 23:25 UTC · Assigner: apple
- CVSS: 6.1 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS: 7.1%, 94th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2021-11-03, federal due date 2021-11-17, ransomware use: Unknown

## Description

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..

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Apple: iOS
- Apple: iOS and iPadOS
- Apple: watchOS

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-1879)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2021-1879)
- [https://support.apple.com/en-us/HT212256](https://support.apple.com/en-us/HT212256)
- [https://support.apple.com/en-us/HT212257](https://support.apple.com/en-us/HT212257)
- [https://support.apple.com/en-us/HT212258](https://support.apple.com/en-us/HT212258)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2021-1879 · Markdown: https://rewindex.com/cve/CVE-2021-1879.md · JSON: https://rewindex.com/api/v1/cves/CVE-2021-1879 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:49:49.509Z