freeradius: stack-based buffer overflow via long expiration date fields in client X509 certificates

Stack-based buffer overflow in the cbtlsverify function in FreeRADIUS 2.1.10 through 2.1.12, when using TLS-based EAP methods, allows remote attackers to cause a denial of service server crash and possibly execute arbitrary code via a long "not after" timestamp in a client certificate...