Directory traversal vulnerability in admin/skins.php for @lex Guestbook 4.0.2 and earlier allows remote attackers to create files in arbitrary directories via ".." sequences in the (1) aj_skin and (2) skin_edit parameters. NOTE: this can be leveraged for file inclusion by creating a skin file in the lang directory, then referencing that file via the lang parameter to index.php, which passes a sanity check in livre_include.php.

SQL injection vulnerability in index.php in @lex Guestbook 4.0.2 and earlier, when magic_quotes_gpc is disabled, allows remote attackers to execute arbitrary SQL commands via the lang parameter.

PHP remote file inclusion vulnerability in livre_include.php in @lex Guestbook allows remote attackers to execute arbitrary PHP code by modifying the chem_absolu parameter to reference a URL on a remote web server that contains the code.