Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
From VID-A8654F1D-770D-11EB-B87A-901B0EF719AB:
Problem Description:
A regression in the login.access(5) rule processor has the effect
of causing rules to fail to match even when they should not. This
means that rules denying access may be ignored.
Impact:
The configuration in login.access(5) may not be applied, permitting
login access to users even when the system is configured to deny it.
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