WA000-WWA028 A22 - The httpd.conf MinSpareServers directive must be set properly.

Information

These requirements are set to mitigate the effects of several types of denial of service attacks. Although there is some latitude concerning the settings themselves, the requirements attempt to provide reasonable limits for the protection of the web server. If necessary, these limits can be adjusted to accommodate the operational requirement of a given system.

From Apache.org: The MinSpareServers directive sets the desired minimum number of idle child server processes. An idle process is one which is not handling a request. If there are fewer than MinSpareServers idle, then the parent process creates new children at a maximum rate of 1 per second.

Tuning of this parameter should only be necessary on very busy sites. Setting this parameter to a large number is almost always a bad idea.

Solution

Open the httpd.conf file with an editor and search for the following directive:

MinSpareServers

Set the directive to a value of between 5 and 10, add the directive if it does not exist.

It is recommended that the directive be explicitly set to prevent unexpected results if the defaults change with updated software.

See Also

https://iasecontent.disa.mil/stigs/zip/U_Apache_2-2_UNIX_V1R11_STIG.zip

Item Details

References: CAT|II, Rule-ID|SV-36646r2_rule, STIG-ID|WA000-WWA028_A22, Vuln-ID|V-13728

Plugin: Unix

Control ID: 9b18a2888da364604a9ac9da4133c84bbcb9671f3b48ad66ef47e7ed5ef5621f