Relying party implementations are an important component of RPKI: they fetch and validate the signed authorizations mapping prefixes to their owners. Border routers use this information to check which Autonomous Systems (ASes) are authorized to originate given prefixes and to enforce Route Origin Validation (ROV) in order to block bogus BGP announcements, preventing accidental and malicious prefix hijacks. In 2021 the RPKI relying party implementations were patched against attacks by malicious publication points. In such attacks the relying parties are stalled processing malformed RPKI objects. In this work we perform a black-box analysis of the patched relying party implementations and find that out of five popular relying parties, two major implementations (Routinator and OctoRPKI) have vulnerabilities that can be exploited to cause large scale blackouts in the RPKI ecosystem. We show that the vulnerabilities we found apply to 84.9% of the networks supporting RPKI. We analyze the code to understand the factors causing the bugs. We show that these vulnerabilities can be exploited to crash the deployed relying parties, disabling RPKI validation and exposing the networks to prefix hijack attacks.
