The httpd.conf MaxSpareServers directive must be set properly.
An XCCDF Rule
Description
<VulnDiscussion>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 MaxSpareServers directive sets the desired maximum number of idle child server processes. An idle process is one which is not handling a request. If there are more than MaxSpareServers idle, then the parent process will kill off the excess processes. 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. If you are trying to set the value equal to or lower than MinSpareServers, Apache will automatically adjust it to MinSpareServers + 1.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility>Web Administrator</Responsibility><IAControls></IAControls>
- ID
- SV-36648r2_rule
- Severity
- Low
- Updated
Remediation - Manual Procedure
Open the httpd.conf file with an editor and search for the following directive:
MaxSpareServers
Set the directive to a value of 10 or less, add the directive if it does not exist.