Simple Machines Forum (SMF) 2.0.6, 1.1.19, and earlier allows remote attackers to impersonate arbitrary users via a Unicode homoglyph character in a username.
Simple Machines Forum (SMF) before 1.1.19 and 2.x before 2.0.6 allows remote attackers to conduct clickjacking attacks via an X-Frame-Options header.
Simple Machines Forum (SMF) before 1.1.19 and 2.x before 2.0.6 allows remote attackers to impersonate arbitrary users via multiple space characters characters.
Unrestricted file upload vulnerability in the avatar upload functionality in Simple Machines Forum before 2.0.6 and 2.1 allows remote authenticated users to execute arbitrary code by uploading a file with an executable extension, then accessing it via a direct request to the file in an unspecified directory.