While investigating bug 64830 it was discovered that Apache Tomcat 10.0.0-M1 to 10.0.0-M9, 9.0.0-M1 to 9.0.39 and 8.5.0 to 8.5.59 could re-use an HTTP request header value from the previous stream received on an HTTP/2 connection for the request associated with the subsequent stream. While this would most likely lead to an error and the closure of the HTTP/2 connection, it is possible that information could leak between requests.

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 7.0.47, 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.

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.

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 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.

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.

Multiple cross-site scripting (XSS) vulnerabilities in examples/servlet/CookieExample in Apache Tomcat 3.3 through 3.3.2 allow remote attackers to inject arbitrary web script or HTML via the (1) Name or (2) Value field, related to error messages.

Apache Tomcat before 5.x allows remote attackers to cause a denial of service (application crash) via a crafted AJP12 packet to TCP port 8007.