FusionAuth fusionauth-samlv2 0.2.3 allows remote attackers to forge messages and bypass authentication via a SAML assertion that lacks a Signature element, aka a “Signature exclusion attack”.
packetstormsecurity.com/files/159454/FusionAuth-SAMLv2-0.2.3-Message-Forging.html
seclists.org/fulldisclosure/2020/Oct/1
compass-security.com/fileadmin/Research/Advisories/2020-06_CSNC-2020-002_FusionAuth_Signature_Exclusion_Attack.txt
github.com/SAMLRaider/SAMLRaider
www.nds.ruhr-uni-bochum.de/media/nds/veroeffentlichungen/2012/08/22/BreakingSAML_3.pdf