libspf2 buffer overflow vulnerability (CNVD-2022-19089)

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. This prevents email forgery commonly used by spammers, scammers and email viruses/worms. libspf2 suffers from a buffer overflow vulnerability that could be exploited by remote attackers to execute arbitrary code using a specific SPF DNS record.