Multiple cross-site scripting (XSS) vulnerabilities in Leif M. Wright's Blog 3.5 allow remote attackers to inject arbitrary web script or HTML via the (1) Referer and (2) User-Agent HTTP headers, which are stored in a log file and not sanitized when the administrator views the "Log" page, possibly using the ViewCommentsLog function.

Leif M. Wright's Blog 3.5 does not make a password comparison when authenticating an administrator via a cookie, which allows remote attackers to bypass login authentication, probably by setting the blogAdmin cookie.

Leif M. Wright's Blog 3.5 stores the config file and other txt files under the web root with insufficient access control, which allows remote attackers to read the administrator's password.

Leif M. Wright's Blog 3.5 allows remote authenticated users with administrative privileges to execute arbitrary programs, including shell commands, by configuring the sendmail path to a malicious pathname.