Description
ext/filter in PHP 5.2.0, when FILTER_SANITIZE_STRING is used with the FILTER_FLAG_STRIP_LOW flag, does not properly strip HTML tags, which allows remote attackers to conduct cross-site scripting (XSS) attacks via HTML with a '<' character followed by certain whitespace characters, which passes one filter but is collapsed into a valid tag, as demonstrated using %0b.
Remediation
References
Related Vulnerabilities
WordPress Plugin Telefication Server-Side Request Forgery (1.8.0)
WordPress Uncontrolled Resource Consumption Vulnerability (CVE-2018-6389)
phpList Unrestricted Upload of File with Dangerous Type Vulnerability (CVE-2020-22249)
MyBB Inclusion of Functionality from Untrusted Control Sphere Vulnerability (CVE-2018-1000502)