It has been reported that Fresh Guest Book is prone to a remote HTML injection vulnerability. This issue is due to a failure of the application to properly sanitize user supplied form input.
An attacker may exploit the aforementioned vulnerabilities to execute arbitrary script code in the browser of an unsuspecting user. It may be possible to steal the unsuspecting user's cookie-based authentication credentials, as well as other sensitive information. Other attacks may also be possible.
Fresh Guestbook is contains a flaw that allows a remote cross site scripting attack. The flaw exists because the application does not validate the name variable upon submission to the "guest.cgi" script. This could allow a user to create a specially crafted URL that would execute arbitrary code in a user's browser within the trust relationship between the browser and the server, leading to a loss of integrity.
Currently, there are no known upgrades, patches, or workarounds available to correct this issue.