The Thecus NAS server N8800 with firmware 5.03.01 allows remote attackers to execute arbitrary commands via a get_userid action with shell metacharacters in the username parameter.
Improper Neutralization of Special Elements used in an OS Command The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.