(RHSA-2012:0041) Moderate: jbossweb security update

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

Multiple flaws were found in the way JBoss Web Server handled HTTP DIGEST
authentication. These flaws weakened the JBoss Web Server 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)

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 Server 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 org.apache.tomcat.util.http.Parameters.MAX_COUNT and
org.apache.tomcat.util.http.MimeHeaders.MAX_COUNT system properties in
“jboss-as/server/[PROFILE]/deploy/properties-service.xml”. (CVE-2011-4858)

A flaw was found in the way JBoss Web Server 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 Server 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 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
Application Platform’s “jboss-as/server/[PROFILE]/deploy/” directory, along
with all other customized configuration files.

All users of JBoss Enterprise Application Platform 4.3.0 CP10 as provided
from the Red Hat Customer Portal are advised to install this update.