(RHSA-2011:1342) Critical: thunderbird security update

Mozilla Thunderbird is a standalone mail and newsgroup client.

Several flaws were found in the processing of malformed HTML content. An
HTML mail message containing malicious content could cause Thunderbird to
crash or, potentially, execute arbitrary code with the privileges of the
user running Thunderbird. (CVE-2011-2995)

A flaw was found in the way Thunderbird processed the “Enter” keypress
event. A malicious HTML mail message could present a download dialog while
the key is pressed, activating the default “Open” action. A remote attacker
could exploit this vulnerability by causing the mail client to open
malicious web content. (CVE-2011-2372)

A flaw was found in the way Thunderbird handled Location headers in
redirect responses. Two copies of this header with different values could
be a symptom of a CRLF injection attack against a vulnerable server.
Thunderbird now treats two copies of the Location, Content-Length, or
Content-Disposition header as an error condition. (CVE-2011-3000)

A flaw was found in the way Thunderbird handled frame objects with certain
names. An attacker could use this flaw to cause a plug-in to grant its
content access to another site or the local file system, violating the
same-origin policy. (CVE-2011-2999)

An integer underflow flaw was found in the way Thunderbird handled large
JavaScript regular expressions. An HTML mail message containing malicious
JavaScript could cause Thunderbird to access already freed memory, causing
Thunderbird to crash or, potentially, execute arbitrary code with the
privileges of the user running Thunderbird. (CVE-2011-2998)

All Thunderbird users should upgrade to this updated package, which
resolves these issues. All running instances of Thunderbird must be
restarted for the update to take effect.