[SECURITY] CVE-2015-5345 Apache Tomcat Directory disclosure

CVE-2015-5345 Apache Tomcat Directory disclosure

Severity: Low

Vendor: The Apache Software Foundation

Versions Affected:
- - Apache Tomcat 6.0.0 to 6.0.44
- - Apache Tomcat 7.0.0 to 7.0.66
- - Apache Tomcat 8.0.0.RC1 to 8.0.29
- - Apache Tomcat 9.0.0.M1
- - Earlier, unsupported Tomcat versions may be affected

Description:
When accessing a directory protected by a security constraint with a URL
that did not end in a slash, Tomcat would redirect to the URL with the
trailing slash thereby confirming the presence of the directory before
processing the security constraint. It was therefore possible for a user
to determine if a directory existed or not, even if the user was not
permitted to view the directory. The issue also occurred at the root of
a web application in which case the presence of the web application was
confirmed, even if a user did not have access.

The solution was to implement the redirect in the DefaultServlet so that
any security constraints and/or security enforcing Filters were
processed before the redirect. The Tomcat team recognised that moving
the redirect could cause regressions to two new Context configuration
options (mapperContextRootRedirectEnabl
ed and
mapperDirectoryRedirectEnabled) were introduced. The initial default was
false for both since this was more secure. However, due to regressions
such as Bug 58765 [1] the default for mapperContextRootRedirectEnabled
was later changed to true since it was viewed that the regression was
more serious than the security risk of associated with being able to
determine if a web application was deployed at a given path.

Mitigation:
Users of affected versions should apply one of the following mitigations
- - Upgrade to Apache Tomcat 9.0.0.M3 or later
  (9.0.0.M2 has the fix but was not released)
- - Upgrade to Apache Tomcat 8.0.30 or later
- - Upgrade to Apache Tomcat 7.0.67 or later
- - Upgrade to Apache Tomcat 6.0.45 or later


Credit:
This issue was discovered by Mark Koek of QCSec.

References:
[1] https://bz.apache.org/bugzilla/show_bug.cgi?id=58765
[2] http://tomcat.apache.org/security-9.html
[3] http://tomcat.apache.org/security-8.html
[4] http://tomcat.apache.org/security-7.html
[5] http://tomcat.apache.org/security-6.html