Apache Tomcat before 6.0.39, 7.x before 7.0.50, and 8.x before 8.0.0-RC10 allows attackers to obtain "Tomcat internals" information by leveraging the presence of an untrusted web application with a context.xml, web.xml, *.jspx, *.tagx, or *.tld XML document containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.

Apache Tomcat before 6.0.39, 7.x before 7.0.50, and 8.x before 8.0.0-RC10 processes chunked transfer coding without properly handling (1) a large total amount of chunked data or (2) whitespace characters in an HTTP header value within a trailer field, which allows remote attackers to cause a denial of service by streaming data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-3544.

Apache Tomcat before 6.0.39, 7.x before 7.0.47, and 8.x before 8.0.0-RC3, when an HTTP connector or AJP connector is used, does not properly handle certain inconsistent HTTP request headers, which allows remote attackers to trigger incorrect identification of a request's length and conduct request-smuggling attacks via (1) multiple Content-Length headers or (2) a Content-Length header and a "Transfer-Encoding: chunked" header. NOTE: this vulnerability exists because of an incomplete fix for CVE-2005-2090.

Cross-site request forgery (CSRF) vulnerability in the Manager application in Apache Tomcat 5.5.25 and earlier allows remote attackers to hijack the authentication of administrators for requests that manipulate application deployment via the POST method, as demonstrated by a /manager/html/undeploy?path= URI. NOTE: the vendor disputes the significance of this report, stating that "the Apache Tomcat Security team has not accepted any reports of CSRF attacks against the Manager application ... as they require a reckless system administrator.

The Windows installer for Apache Tomcat 6.0.0 through 6.0.20, 5.5.0 through 5.5.28, and possibly earlier versions uses a blank default password for the administrative user, which allows remote attackers to gain privileges.

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when FORM authentication is used, allows remote attackers to enumerate valid usernames via requests to /j_security_check with malformed URL encoding of passwords, related to improper error checking in the (1) MemoryRealm, (2) DataSourceRealm, and (3) JDBCRealm authentication realms, as demonstrated by a % (percent) value for the j_password parameter.

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when the Java AJP connector and mod_jk load balancing are used, allows remote attackers to cause a denial of service (application outage) via a crafted request with invalid headers, related to temporary blocking of connectors that have encountered errors, as demonstrated by an error involving a malformed HTTP Host header.

The JK Connector (aka mod_jk) 1.2.0 through 1.2.26 in Apache Tomcat allows remote attackers to obtain sensitive information via an arbitrary request from an HTTP client, in opportunistic circumstances involving (1) a request from a different client that included a Content-Length header but no POST data or (2) a rapid series of requests, related to noncompliance with the AJP protocol's requirements for requests containing Content-Length headers.

Cross-site scripting (XSS) vulnerability in jsp/cal/cal2.jsp in the calendar application in the examples web application in Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18 allows remote attackers to inject arbitrary web script or HTML via the time parameter, related to "invalid HTML."

Apache Tomcat 5.5.0 and 4.1.0 through 4.1.31 allows remote attackers to bypass an IP address restriction and obtain sensitive information via a request that is processed concurrently with another request but in a different thread, leading to an instance-variable overwrite associated with a "synchronization problem" and lack of thread safety, and related to RemoteFilterValve, RemoteAddrValve, and RemoteHostValve.

Apache Tomcat 6.0.0 to 6.0.13, 5.5.0 to 5.5.24, 5.0.0 to 5.0.30, 4.1.0 to 4.1.36, and 3.3 to 3.3.2 treats single quotes ("'") as delimiters in cookies, which might cause sensitive information such as session IDs to be leaked and allow remote attackers to conduct session hijacking attacks.

Apache Tomcat 6.0.0 to 6.0.13, 5.5.0 to 5.5.24, 5.0.0 to 5.0.30, 4.1.0 to 4.1.36, and 3.3 to 3.3.2 does not properly handle the \" character sequence in a cookie value, which might cause sensitive information such as session IDs to be leaked to remote attackers and enable session hijacking attacks.

Multiple cross-site scripting (XSS) vulnerabilities in the (1) Manager and (2) Host Manager web applications in Apache Tomcat 4.0.0 through 4.0.6, 4.1.0 through 4.1.36, 5.0.0 through 5.0.30, 5.5.0 through 5.5.24, and 6.0.0 through 6.0.13 allow remote authenticated users to inject arbitrary web script or HTML via a parameter name to manager/html/upload, and other unspecified vectors.

Apache Tomcat 4.0.5 and earlier, when using both the invoker servlet and the default servlet, allows remote attackers to read source code for server files or bypass certain protections, a variant of CAN-2002-1148.

Tomcat 4.0 through 4.1.12, using mod_jk 1.2.1 module on Apache 1.3 through 1.3.27, allows remote attackers to cause a denial of service (desynchronized communications) via an HTTP GET request with a Transfer-Encoding chunked field with invalid values.

The default servlet (org.apache.catalina.servlets.DefaultServlet) in Tomcat 4.0.4 and 4.1.10 and earlier allows remote attackers to read source code for server files via a direct request to the servlet.