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, proxy authentication incorrectly reported HTTP proxies received credentials securely. This issue was addressed through improved warnings.
Conclusion & alert: CVE-2016-4642 is rated Moderate Risk (43.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.34%).Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2016-4642
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).