It was found that a fix for a previous security flaw introduced a regression that could cause a denial of service in Tomcat 7. A remote attacker could use this flaw to consume an excessive amount of CPU on the Tomcat server by sending a specially crafted request to that server. It was found that when Tomcat 7 processed a series of HTTP requests in which at least one request contained either multiple content-length headers, or one content-length header with a chunked transfer-encoding header, Tomcat would incorrectly handle the request. A remote attacker could use this flaw to poison a web cache, perform cross-site scripting (XSS) attacks, or obtain sensitive information from other requests.