joomla -- multiple vulnerabilities

A Secunia Advisory reports:
joomla can be exploited to conduct session fixation
attacks, cross-site scripting attacks or HTTP response
splitting attacks.
Certain unspecified input passed in com_search, com_content and
mod_login is not properly sanitised before being returned to a
user. This can be exploited to execute arbitrary HTML and script
code in a user’s browser session in context of an affected
site.
Input passed to the url parameter is not properly sanitised
before being returned to the user. This can be exploited to insert
arbitrary HTTP headers, which will be included in a response sent
to the user, allowing for execution of arbitrary HTML and script
code in a user’s browser session in context of an affected
site.
An error exists in the handling of sessions and can be exploited
to hijack another user’s session by tricking the user into logging
in after following a specially crafted link.