Apache Tomcat before 6.0.40, 7.x before 7.0.54, and 8.x before 8.0.6 does not properly constrain the class loader that accesses the XML parser used with an XSLT stylesheet, which allows remote attackers to (1) read arbitrary files via a crafted web application that provides an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue, or (2) read files associated with different web applications on a single Tomcat instance via a crafted web application.

Integer overflow in java/org/apache/tomcat/util/buf/Ascii.java in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4, when operated behind a reverse proxy, allows remote attackers to conduct HTTP request smuggling attacks via a crafted Content-Length HTTP header.

java/org/apache/catalina/servlets/DefaultServlet.java in the default servlet in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4 does not properly restrict XSLT stylesheets, which allows remote attackers to bypass security-manager restrictions and read arbitrary files via a crafted web application that provides an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.

Integer overflow in the parseChunkHeader function in java/org/apache/coyote/http11/filters/ChunkedInputFilter.java in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4 allows remote attackers to cause a denial of service (resource consumption) via a malformed chunk size in chunked transfer coding of a request during the streaming of data.

MultipartStream.java in Apache Commons FileUpload before 1.3.1, as used in Apache Tomcat, JBoss Web, and other products, allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a crafted Content-Type header that bypasses a loop's intended exit conditions.

Apache Tomcat 7.x uses world-readable permissions for the log directory and its files, which might allow local users to obtain sensitive information by reading a file. NOTE: One Tomcat distributor has stated "The tomcat log directory does not contain any sensitive information."

Apache Tomcat through 7.0.x allows remote attackers to cause a denial of service (daemon outage) via partial HTTP requests, as demonstrated by Slowloris.