Check: WA000-WWA030 A24
Apache Server 2.4 Unix:
WA000-WWA030 A24
(in version v1 r1)
Title
The httpd.conf MaxSpareServers directive must be set properly. (Cat III impact)
Discussion
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 HTTP Server will automatically adjust it to MinSpareServers + 1.
Check Content
To view the MaxSpareServers value enter the following command: find / -name httpd.conf -print -exec grep -H -i "MaxSpareServers" {} \; If the value of "MaxSpareServers" is not 10 or less, this is a finding. If the directive does not exist, this is NOT a finding because it will default to 10. It is recommended that the directive be explicitly set to prevent unexpected results if the defaults change with updated software. NOTE: This vulnerability can be documented locally with the ISSM/ISSO if the site has operational reasons for the use of increased value. If the site has this documentation, this should be marked as Not a Finding.
Fix Text
Edit the httpd.conf file and set the value of "MaxSpareServers" to a value of 10 or less, add the directive if it does not exist.
Additional Identifiers
Rule ID:
Vulnerability ID: V-13729
Group Title:
Expert Comments
CCIs
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Controls
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