The DIR-600 / DIR-300 revB / DIR-815 / DIR-645 / DIR-412 / DIR-456U / DIR-110 have multiple vulnerabilities that allow a malicious attacker to run device operating system commands if authenticated or discover information about the device which may help further exploits to be identified and used.
For more information and firmware -->
https://securityadvisories.dlink.com/announcement/publication.aspx?name=SAP10086