The process_chpw_request function in schpw.c in the password-changing functionality in kadmind in MIT Kerberos 5 (aka krb5) 1.7 through 1.9 frees an invalid pointer, which allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a crafted request that triggers an error condition.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.