The quoted-printable decoder in bogofilter 0.17.4 to 0.92.7 allows remote attackers to cause a denial of service (application crash) via mail headers that cause a line feed (LF) to be replaced by a null byte that is written to an incorrect memory address.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17916
http://bogofilter.sourceforge.net/security/bogofilter-SA-2004-01