Multiple SQL injection vulnerabilities in EllisLab ExpressionEngine before 2.9.1 allow remote authenticated users to execute arbitrary SQL commands via the (1) column_filter or (2) category[] parameter to system/index.php or the (3) tbl_sort[0][] parameter in the comment module to system/index.php.
Cross-site scripting (XSS) vulnerability in system/index.php in ExpressionEngine 1.6.4 through 1.6.6, and possibly earlier versions, allows remote attackers to inject arbitrary web script or HTML via the avatar parameter.
Cross-site scripting (XSS) vulnerability in index.php in ExpressionEngine 1.2.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the URL parameter.
CRLF injection vulnerability in index.php in ExpressionEngine 1.2.1 and earlier allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the URL parameter.