Apache HTTPd vulnerabilities

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Several vulnerabilities have been found in the Apache HTTPD Server:


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

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

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

ProxyPassMatch ^/mail(.*) http://internal-host$1

is still insecure and should be replaced by one of the following

ProxyPassMatch ^/mail(/.*) http://internal-host$1
ProxyPassMatch ^/mail/(.*) http://internal-host/$1


An apache2 child process could cause the parent process to crash
during shutdown. This is a violation of the privilege separation
between the apache2 processes and could potentially be used to worsen
the impact of other vulnerabilities.


The response message for error code 400 (bad request) could be used to
expose “httpOnly” cookies. This could allow a remote attacker using
cross site scripting to steal authentication cookies.

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