CVE-2016-4745: Apple Mac OS X

Medium severity, CVSS 5.3. EPSS: 1.8% chance of exploitation in the next 30 days.

The Kerberos 5 (aka krb5) PAM module in Apple OS X before 10.12 does not use constant-time operations for determining username validity, which makes it easier for remote attackers to enumerate user accounts via a timing side-channel attack.

Affected products

• Apple Mac OS X: up to and including 10.11.6

Published 2016-09-25. Last modified 2026-06-17.