PHPIDS before 0.7 does not properly implement Regular Expression Denial of Service (ReDoS) filters, which allows remote attackers to bypass rulesets and add PHP sequences to a file via unspecified vectors.

PHPIDS 0.6.5 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by tests/IDS/VersionTest.php and certain other files.

PHPIDS before 20070703 does not properly handle use of the substr method in (1) document.location.search and (2) document.referrer; (3) certain use of document.location.hash; (4) certain "window[eval" and similar expressions; (5) certain Function expressions; (6) certain '=' expressions, as demonstrated by a 'whatever="something"' sequence; and (7) certain "with" expressions, which allows remote attackers to inject arbitrary web script.

PHPIDS does not properly handle certain code containing newlines, as demonstrated by a try/catch block within a loop, which allows user-assisted remote attackers to inject arbitrary web script.

PHPIDS before 20070703 does not properly handle (1) arithmetic expressions and (2) unclosed comments, which allows remote attackers to inject arbitrary web script.

PHPIDS before 20070703 does not properly handle setting the .text property of a SCRIPT element before its attachment to the DOM, which allows remote attackers to inject arbitrary web script.