OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first <Signature> element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:N8.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NOther