CVE-2016-4644

Name: CVE-2016-4644
Creator: NVD / NIST
Published: 2019-01-11T18:29:00.453+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 1.33%

Last modified Jun 17, 2026

CVE-2016-4644 is a vulnerability of currently unknown severity. In iOS before 9.3.3, tvOS before 9.2.2, and OS X El Capitan before v10.11.6 and Security Update 2016-004, a downgrade issue existed with HTTP authentication credentials saved in Keychain. This issue was addressed by storing the authentication types with the credentials.. EPSS estimates a 1.33% chance of exploitation in the next 30 days.

Description

In iOS before 9.3.3, tvOS before 9.2.2, and OS X El Capitan before v10.11.6 and Security Update 2016-004, a downgrade issue existed with HTTP authentication credentials saved in Keychain. This issue was addressed by storing the authentication types with the credentials.

Metrics

EPSS Probability

1.33%

67.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Apple	Apple Tv	< 9.2.2
Apple	Iphone Os	< 9.3.3
Apple	Mac Os	>= 10.11.0, < 10.11.6

References

https://support.apple.com/HT206902Vendor Advisory
https://support.apple.com/HT206903Vendor Advisory
https://support.apple.com/HT206905Vendor Advisory
https://support.apple.com/HT206902Vendor Advisory
https://support.apple.com/HT206903Vendor Advisory
https://support.apple.com/HT206905Vendor Advisory

Timeline

Published: Jan 11, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2016-4644?

How severe is CVE-2016-4644?

Severity scoring for CVE-2016-4644 is pending analysis. The EPSS model estimates a 1.33% probability of exploitation in the next 30 days.

How do I fix CVE-2016-4644?

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-2016-4644?

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

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Source: NVD / NIST