2020 Nomination for Best Server-Side Bug


Qualys Security Advisory Team

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server because the server code launches the client code during bounce handling.

RCE in OpenSMTPD’s Default Install, CVE-2020-8794