Summary of security impact levels for Apache Tomcat
The Apache Tomcat Security Team rates the impact of each security flaw
that affects Tomcat. We've chosen a rating scale quite similar to those
used by other major vendors in order to be consistent. Basically the goal
of the rating system is to answer the question "How worried should I be
about this vulnerability?".
Note that the rating chosen for each flaw is the worst possible case
across all architectures. To determine the exact impact of a particular
vulnerability on your own systems you will still need to read the security
advisories to find out more about the flaw.
We use the following descriptions to decide on the impact rating to give
A vulnerability rated with a Critical impact is one which could
potentially be exploited by a remote attacker to get Tomcat to execute
arbitrary code (either as the user the server is running as, or root).
These are the sorts of vulnerabilities that could be exploited
automatically by worms.
Important / High
A vulnerability rated as Important (or High) impact is one which could
result in the compromise of data or availability of the server. For
Tomcat this includes issues that allow an easy remote denial of service
(something that is out of proportion to the attack or with a lasting
consequence), access to arbitrary files outside of the context root, or
access to files that should be otherwise prevented by limits or
A vulnerability is likely to be rated as Moderate if there is significant
mitigation to make the issue less of an impact. This might be because the
flaw does not affect likely configurations, or it is a configuration that
isn't widely used, or where a remote user must be authenticated in order
to exploit the issue. Flaws that allow Tomcat to serve directory listings
instead of index files and cross-site scripting issues are included here.
All other security flaws are classed as a Low impact. This rating is used
for issues that are believed to be extremely hard to exploit, or where an
exploit gives minimal consequences.