(RHSA-2012:0076) Important: jbossweb security update

JBoss Web is a web container based on Apache Tomcat. It provides a single
deployment platform for the JavaServer Pages (JSP) and Java Servlet
technologies.

A flaw was found in the way JBoss Web handled UTF-8 surrogate pair
characters. If JBoss Web was hosting an application with UTF-8 character
encoding enabled, or that included user-supplied UTF-8 strings in a
response, a remote attacker could use this flaw to cause a denial of
service (infinite loop) on the JBoss Web server. (CVE-2011-4610)

It was found that the Java hashCode() method implementation was susceptible
to predictable hash collisions. A remote attacker could use this flaw to
cause JBoss Web to use an excessive amount of CPU time by sending an HTTP
request with a large number of parameters whose names map to the same hash
value. This update introduces a limit on the number of parameters and
headers processed per request to mitigate this issue. The default limit is
512 for parameters and 128 for headers. These defaults can be changed by
setting the “-Dorg.apache.tomcat.util.http.Parameters.MAX_COUNT=x” and
“-Dorg.apache.tomcat.util.http.MimeHeaders.MAX_COUNT=x” system properties
as JAVA_OPTS entries in “jboss-as-web/bin/run.conf”. (CVE-2011-4858)

It was found that JBoss Web did not handle large numbers of parameters and
large parameter values efficiently. A remote attacker could make a JBoss
Web server use an excessive amount of CPU time by sending an HTTP request
containing a large number of parameters or large parameter values. This
update introduces limits on the number of parameters and headers processed
per request to address this issue. Refer to the CVE-2011-4858 description
for information about the org.apache.tomcat.util.http.Parameters.MAX_COUNT
and org.apache.tomcat.util.http.MimeHeaders.MAX_COUNT system properties.
(CVE-2012-0022)

Multiple flaws were found in the way JBoss Web handled HTTP DIGEST
authentication. These flaws weakened the JBoss Web HTTP DIGEST
authentication implementation, subjecting it to some of the weaknesses of
HTTP BASIC authentication, for example, allowing remote attackers to
perform session replay attacks. (CVE-2011-1184, CVE-2011-5062,
CVE-2011-5063, CVE-2011-5064)

A flaw was found in the way JBoss Web handled sendfile request attributes
when using the HTTP APR (Apache Portable Runtime) or NIO (Non-Blocking I/O)
connector. A malicious web application running on a JBoss Web instance
could use this flaw to bypass security manager restrictions and gain access
to files it would otherwise be unable to access, or possibly terminate the
Java Virtual Machine (JVM). (CVE-2011-2526)

Red Hat would like to thank NTT OSSC for reporting CVE-2011-4610; oCERT for
reporting CVE-2011-4858; and the Apache Tomcat project for reporting
CVE-2011-2526. oCERT acknowledges Julian Wälde and Alexander Klink as the
original reporters of CVE-2011-4858.

Warning: Before applying this update, back up your JBoss Enterprise Web
Platform’s “jboss-as-web/server/[PROFILE]/deploy/” directory and any other
customized configuration files.

Users of JBoss Enterprise Web Platform 5.1.2 on Red Hat Enterprise Linux 4,
5, and 6 should upgrade to these updated packages, which correct these
issues. The JBoss server process must be restarted for this update to take
effect.