Luca "ikki" Carettoni and Luca "Daath" De Fulgentis have reported some vulnerabilities in Simple PHP Blog, which can be exploited by malicious people to conduct cross-site scripting attacks and by malicious users to compromise a vulnerable system.

1) Input passed to the "user_colors[bg_color]" parameter in the file \themes\<theme name>\user_style.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

Successful exploitation requires that "register_globals" is enabled.

2) The upload_img_cgi.php script does not correctly restrict certain types of uploaded files. This can be exploited to e.g. execute arbitrary PHP code by uploading a specially crafted PHP script that contains the GIF magic number.

This is related to:
SA16598

The vulnerabilities are reported in versions prior to 0.5.1.

Solution
Update to version 0.5.1.

Provided and/or discovered by
Luca "ikki" Carettoni and Luca "Daath" De Fulgentis, SecureNetwork.IT

Original Advisory
Simple PHP Blog:
http://www.simplephpblog.com/index.php?entry=entry070923-004446

SecureNetwork.IT:
http://www.securenetwork.it/ricerca/advisory/download/SN-2007-03.txt

Other references
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers