CVE-2021-1879

Name: CVE-2021-1879
Creator: NVD / NIST
Published: 2021-04-02T19:15:20.77+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10Actively ExploitedEPSS 7.08%

Last modified Jun 17, 2026

CVE-2021-1879 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 7.08% chance of exploitation in the next 30 days.

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..

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

7.08%

93.4th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Ipados	< 14.4.2
Apple	Iphone Os	< 12.5.2
Apple	Iphone Os	>= 13.0, < 14.4.2
Apple	Watchos	< 7.3.3

References

https://support.apple.com/en-us/HT212256Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212257Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212258Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212256Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212257Release Notes, Vendor Advisory
https://support.apple.com/en-us/HT212258Release Notes, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879US Government Resource

Timeline

Published: Apr 2, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-1879?

How severe is CVE-2021-1879?

CVE-2021-1879 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 7.08% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-1879?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-1879?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST