Directory traversal vulnerability in index.php in CodeIgniter 1.5.3 before 20070628, when enable_query_strings is true, allows remote attackers to read arbitrary files via a .. (dot dot) in the c parameter.

CRLF injection vulnerability in the redirect function in url_helper.php in CodeIgniter 1.5.3 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in an unspecified parameter, as demonstrated by a Set-Cookie header.

Cross-site scripting (XSS) vulnerability in CodeIgniter 1.5.3 before 20070626 allows remote attackers to inject arbitrary web script or HTML via (1) String.fromCharCode and (2) malformed nested tag manipulations in an unspecified component, related to insufficient sanitization by the xss_clean function.

The _sanitize_globals function in CodeIgniter 1.5.3 before 20070628 allows remote attackers to unset arbitrary global variables with unspecified impact, as demonstrated by a _SERVER cookie.