Critical: firefox security update
Security Advisory: Critical
Updated firefox packages that fix several security issues are now available
for Red Hat Enterprise Linux 4 and 5.
The Red Hat Security Response Team has rated this update as having critical
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.
Mozilla Firefox is an open source web browser. XULRunner provides the XUL
Runtime environment for Mozilla Firefox.
Several flaws were found in the processing of malformed web content. A web
page containing malicious content could cause Firefox to crash or,
potentially, execute arbitrary code with the privileges of the user running
Firefox. (CVE-2010-3169, CVE-2010-2762)
Several use-after-free and dangling pointer flaws were found in Firefox. A
web page containing malicious content could cause Firefox to crash or,
potentially, execute arbitrary code with the privileges of the user running
Firefox. (CVE-2010-2760, CVE-2010-2766, CVE-2010-2767, CVE-2010-3167,
CVE-2010-3168)
Multiple buffer overflow flaws were found in Firefox. A web page containing
malicious content could cause Firefox to crash or, potentially, execute
arbitrary code with the privileges of the user running Firefox.
(CVE-2010-2765, CVE-2010-3166)
Multiple cross-site scripting (XSS) flaws were found in Firefox. A web page
containing malicious content could cause Firefox to run JavaScript code
with the permissions of a different website. (CVE-2010-2768, CVE-2010-2769)
A flaw was found in the Firefox XMLHttpRequest object. A remote site could
use this flaw to gather information about servers on an internal private
network. (CVE-2010-2764)
For technical details regarding these flaws, refer to the Mozilla security
advisories for Firefox 3.6.9. You can find a link to the Mozilla advisories
in the References section of this erratum.
Note: After installing this update, Firefox will fail to connect (with
HTTPS) to a server using the SSL DHE (Diffie-Hellman Ephemeral) key
exchange if the server's ephemeral key is too small. Connecting to such
servers is a security risk as an ephemeral key that is too small makes the
SSL connection vulnerable to attack. Refer to the Solution section for
further information.
All Firefox users should upgrade to these updated packages, which contain
Firefox version 3.6.9, which corrects these issues. After installing the
update, Firefox must be restarted for the changes to take effect.
Before applying this update, make sure all previously-released errata
relevant to your system have been applied.
This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259
If you encounter the condition where Firefox fails to connect to a
server that has an ephemeral key that is too small, you can try
connecting using a cipher suite with a different key exchange algorithm
by disabling all DHE cipher suites in Firefox:
1) Type about:config in the URL bar and press the Enter key.
2) In the Filter search bar, type ssl3.dhe
3) For all preferences now presented, double-click the true value to
change the value to false.
Note: This change would affect connections to all HTTPS servers.
Vulmon