Black Hat Europe 2025 | RMPocalypse: A Catch-22 Breaking AMDs Confidential Computing

AMD SEV-SNP offers confidential computing in form of confidential VMs, such that the untrusted hypervisor cannot tamper with its confidentiality and integrity. SEV-SNP, the latest addition, ensures integrity via the Reverse Map Table (RMP) that stops the hypervisor from tampering guest page mappings. AMD uses RMP entries to protect the rest of the RMP, thus causing a Catch-22 during the RMP setup phase. To address this, SEV-SNP relies on AMD's Platform Security Processor (PSP), that resides next to the x86 cores executing SEV-SNP VMs, to perform the RMP initialization. We present RMPocalypse, a novel attack that shows insufficiency during RMP initialization and exploits it to break not only integrity but also confidentiality guarantees of SEV-SNP. We demonstrate RMPocalypse by enabling debug on production-mode CVMs, faking attestation, VMSA state rollback, and code injection By: Benedict Markus Schlüter | PhD Student, ETH Zurich