S4mi has discovered some vulnerabilities in JBlog, which can be exploited by malicious people to conduct cross-site scripting attacks, bypass certain security restrictions, and conduct SQL injection attacks.

1) A vulnerability is caused due to improper authentication verification in admin/ajoutaut.php. This can be exploited to create new administrators and other user types, without having any valid user credentials.

2) Input passed to the "id" parameter in index.php (when "pcomm" is set to "com") and the "search" parameter in recherche.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.

3) Input passed to the "id" parameter in index.php is not properly sanitised before being used in SQL queries. This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

Successful exploitation of this vulnerability allows e.g. retrieving administrator usernames and password hashes, but requires that "magic_quotes_gpc" is disabled.

4) Input passed to the "id" parameter in admin/modifpost.php is not properly sanitised before being used in SQL queries. This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

Successful exploitation of this vulnerability allows e.g. retrieving administrator usernames and password hashes, but requires valid administrator credentials and that "magic_quotes_gpc" is disabled.

The vulnerabilities are confirmed in version 1.0. Other versions may also be affected.

Solution
Restrict access to the admin/ directory (e.g. with ".htaccess"). Edit the source code to ensure that input is properly sanitised.

Provided and/or discovered by
S4mi

Changelog
Further details available to Secunia VIM customers

Original Advisory
1-2) http://milw0rm.com/exploits/4211
3-4) http://milw0rm.com/exploits/4408

Deep Links
Links available to Secunia VIM customers