Remote code execution is possible with Apache Tomcat before 6.0.48, 7.x before 7.0.73, 8.x before 8.0.39, 8.5.x before 8.5.7, and 9.x before 9.0.0.M12 if JmxRemoteLifecycleListener is used and an attacker can reach JMX ports. The issue exists because this listener wasn't updated for consistency with the CVE-2016-3427 Oracle patch that affected credential types.
The code in Apache Tomcat 9.0.0.M1 to 9.0.0.M11, 8.5.0 to 8.5.6, 8.0.0.RC1 to 8.0.38, 7.0.0 to 7.0.72, and 6.0.0 to 6.0.47 that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack and/or obtain sensitive information from requests other then their own.
Apache Tomcat 7.x through 7.0.70 and 8.x through 8.5.4, when the CGI Servlet is enabled, follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue. NOTE: the vendor states "A mitigation is planned for future releases of Tomcat, tracked as CVE-2016-5388"; in other words, this is not a CVE ID for a vulnerability.
The Expression Language (EL) implementation in Apache Tomcat 6.x before 6.0.44, 7.x before 7.0.58, and 8.x before 8.0.16 does not properly consider the possibility of an accessible interface implemented by an inaccessible class, which allows attackers to bypass a SecurityManager protection mechanism via a web application that leverages use of incorrect privileges during EL evaluation.
Apache Tomcat 6.x before 6.0.44, 7.x before 7.0.55, and 8.x before 8.0.9 does not properly handle cases where an HTTP response occurs before finishing the reading of an entire request body, which allows remote attackers to cause a denial of service (thread consumption) via a series of aborted upload attempts.
java/org/apache/coyote/http11/filters/ChunkedInputFilter.java in Apache Tomcat 6.x before 6.0.42, 7.x before 7.0.55, and 8.x before 8.0.9 does not properly handle attempts to continue reading data after an error has occurred, which allows remote attackers to conduct HTTP request smuggling attacks or cause a denial of service (resource consumption) by streaming data with malformed chunked transfer coding.
Unrestricted file upload vulnerability in Apache Tomcat 7.x before 7.0.40, in certain situations involving outdated java.io.File code and a custom JMX configuration, allows remote attackers to execute arbitrary code by uploading and accessing a JSP file.
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.
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 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.