Multiple vulnerabilities has been found and corrected in apache
(ASF HTTPD):

The log_cookie function in mod_log_config.c in the mod_log_config
module in the Apache HTTP Server 2.2.17 through 2.2.21, when a threaded
MPM is used, does not properly handle a %{}C format string, which
allows remote attackers to cause a denial of service (daemon crash)
via a cookie that lacks both a name and a value (CVE-2012-0021).

scoreboard.c in the Apache HTTP Server 2.2.21 and earlier might
allow local users to cause a denial of service (daemon crash during
shutdown) or possibly have unspecified other impact by modifying
a certain type field within a scoreboard shared memory segment,
leading to an invalid call to the free function (CVE-2012-0031).

protocol.c in the Apache HTTP Server 2.2.x through 2.2.21 does not
properly restrict header information during construction of Bad
Request (aka 400) error documents, which allows remote attackers to
obtain the values of HTTPOnly cookies via vectors involving a (1)
long or (2) malformed header in conjunction with crafted web script
(CVE-2012-0053).

The updated packages have been upgraded to the latest 2.2.22 version
which is not vulnerable to this issue.

Additionally APR and APR-UTIL has been upgraded to the latest versions
1.4.5 and 1.4.1 respectively which holds many improvments over the
previous versions.