(RHSA-2013:0623) Important: tomcat6 security update

Apache Tomcat is a servlet container.

It was found that when an application used FORM authentication, along with
another component that calls request.setUserPrincipal() before the call to
FormAuthenticator#authenticate() (such as the Single-Sign-On valve), it was
possible to bypass the security constraint checks in the FORM authenticator
by appending “/j_security_check” to the end of a URL. A remote attacker
with an authenticated session on an affected application could use this
flaw to circumvent authorization controls, and thereby access resources not
permitted by the roles associated with their authenticated session.
(CVE-2012-3546)

A flaw was found in the way Tomcat handled sendfile operations when using
the HTTP NIO (Non-Blocking I/O) connector and HTTPS. A remote attacker
could use this flaw to cause a denial of service (infinite loop). The HTTP
blocking IO (BIO) connector, which is not vulnerable to this issue, is used
by default in Red Hat Enterprise Linux 6. (CVE-2012-4534)

Multiple weaknesses were found in the Tomcat DIGEST authentication
implementation, effectively reducing the security normally provided by
DIGEST authentication. A remote attacker could use these flaws to perform
replay attacks in some circumstances. (CVE-2012-5885, CVE-2012-5886,
CVE-2012-5887)

Users of Tomcat should upgrade to these updated packages, which correct
these issues. Tomcat must be restarted for this update to take effect.