Belkin LINKSYS RE6500 devices before 1.0.11.001 allow remote authenticated users to execute arbitrary commands via goform/systemCommand?command= in conjunction with the goform/pingstart program.
bugcrowd.com/disclosures/72d7246b-f77f-4f7f-9bd1-fdc35663cc92/linksys-re6500-unauthenticated-rce-working-across-multiple-fw-versions
downloads.linksys.com/support/assets/releasenotes/ExternalReleaseNotes_RE6500_1.0.012.001.txt
resolverblog.blogspot.com/2020/07/linksys-re6500-unauthenticated-rce-full.html