(RHSA-2002:251) apache security update

The Apache HTTP server is a powerful, full-featured, efficient, and
freely-available Web server.

Buffer overflows in the ApacheBench support program (ab.c) in Apache
versions prior to 1.3.27 allow a malicious Web server to cause a denial of
service and possibly execute arbitrary code via a long response. The
Common Vulnerabilities and Exposures project has assigned the name
CAN-2002-0843 to this issue.

Two cross-site scripting vulnerabilities are present in the error pages
for the default “404 Not Found” error, and for the error response when a
plain HTTP request is received on an SSL port. Both of these issues are
only exploitable if the “UseCanonicalName” setting has been changed to
“Off”, and wildcard DNS is in use. These issues would allow remote
attackers to execute scripts as other Web page visitors, for instance, to
steal cookies. These issues affect versions of Apache 1.3 before 1.3.26,
and versions of mod_ssl before 2.8.12. The Common Vulnerabilities and
Exposures project has assigned the names CAN-2002-0840 and CAN-2002-1157 to
these issues.

The shared memory scoreboard in the HTTP daemon for Apache 1.3, prior to
version 1.3.27, allowed a user running as the “apache” UID to send a
SIGUSR1 signal to any process as root, resulting in a denial of service
(process kill) or other such behavior that would not normally be allowed.
The Common Vulnerabilities and Exposures project has assigned the name
CAN-2002-0839 to this issue.

All users of the Apache HTTP server are advised to upgrade to the
applicable errata packages. For Red Hat Linux Advanced Server 2.1 these
packages include Apache version 1.3.27 which is not vulnerable to
these issues.

Note that the instructions in the “Solution” section of this errata contain
additional steps required to complete the upgrade process.