Debian DSA-2405-1: Apache2 Remote Access Issues Moderate Severity

CVE-2011-3607:

An integer overflow in ap_pregsub() could allow local attackers to
execute arbitrary code at elevated privileges via crafted .htaccess
files.

CVE-2011-3368 CVE-2011-3639 CVE-2011-4317:

The Apache HTTP Server did not properly validate the request URI for
proxied requests. In certain reverse proxy configurations using the
ProxyPassMatch directive or using the RewriteRule directive with the
[P] flag, a remote attacker could make the proxy connect to an
arbitrary server. The could allow the attacker to access internal
servers that are not otherwise accessible from the outside.

The three CVE ids denote slightly different variants of the same
issue.

Note that, even with this issue fixed, it is the responsibility of
the administrator to ensure that the regular expression replacement
pattern for the target URI does not allow a client to append arbitrary
strings to the host or port parts of the target URI. For example, the
configuration

ProxyPassMatch ^/mail(...