CVE-2021-1799

Name: CVE-2021-1799
Creator: NVD / NIST
Published: 2021-04-02T19:15:19.617+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.77%

Last modified Jun 17, 2026

CVE-2021-1799 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. A port redirection issue was addressed with additional port validation. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. EPSS estimates a 1.77% chance of exploitation in the next 30 days.

Description

A port redirection issue was addressed with additional port validation. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. A malicious website may be able to access restricted ports on arbitrary servers.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

1.77%

75.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Apple	Safari	< 14.0.3
Apple	Ipad Os	< 14.4
Apple	Iphone Os	< 14.4
Apple	Macos	>= 11.0.1, < 11.2
Apple	Tvos	< 14.4
Apple	Watchos	< 7.3
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Webkitgtk	Webkitgtk	< 2.30.6

References

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
https://security.gentoo.org/glsa/202104-03Third Party Advisory
https://support.apple.com/en-us/HT212146Vendor Advisory
https://support.apple.com/en-us/HT212147Vendor Advisory
https://support.apple.com/en-us/HT212148Vendor Advisory
https://support.apple.com/en-us/HT212149Vendor Advisory
https://support.apple.com/en-us/HT212152Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
https://security.gentoo.org/glsa/202104-03Third Party Advisory
https://support.apple.com/en-us/HT212146Vendor Advisory
https://support.apple.com/en-us/HT212147Vendor Advisory
https://support.apple.com/en-us/HT212148Vendor Advisory
https://support.apple.com/en-us/HT212149Vendor Advisory
https://support.apple.com/en-us/HT212152Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2021-1799?

How severe is CVE-2021-1799?

CVE-2021-1799 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.77% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1799?

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-2021-1799?

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

Scan your code now

Source: NVD / NIST