libspf2 buffer overflow vulnerability

libspf2 is a library that allows email systems such as Sendmail, Postfix, Exim, Zmailer, and MS Exchange to check SPF records and ensure that email is authorized from its domain. libspf2 suffers from a buffer overflow vulnerability, which stems from the fact that libspf2’s SPF macro can trigger a a buffer overflow, which can be exploited by an attacker to cause a denial of service and possibly run code.