The IBM z/VM TCP/IP PENDINGCONNECTIONLIMIT statement must be properly configured.
Overview
Finding ID
Version
Rule ID
IA Controls
Severity
V-237927
IBMZ-VM-000740
SV-237927r858989_rule
Medium
Description
DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.
Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.
The PENDINGCONNECTIONLIMIT statement defines the maximum number of half-open connections that are allowed at any given time. When a new half-open connection causes this limit to be exceeded, a random current half-open connection is dropped and a SynFlood denial-of-service attack is declared.