modules/rlm_unix/rlm_unix.c in FreeRADIUS before 2.2.0, when unix mode is enabled for user authentication, does not properly check the password expiration in /etc/shadow, which allows remote authenticated users to authenticate using an expired password.

Multiple RADIUS implementations do not properly validate the Vendor-Length of the Vendor-Specific attribute, which allows remote attackers to cause a denial of service (crash) via a Vendor-Length that is less than 2.

Buffer overflow in digest calculation function of multiple RADIUS implementations allows remote attackers to cause a denial of service and possibly execute arbitrary code via shared secret data.