Insufficient validation of the AMD SEV Signing Key (ASK) in the SEND_START command in the SEV Firmware may allow a local authenticated attac

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• amd epyc 7232p firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7251 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7252 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7261 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7262 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7272 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7281 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7282 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 72f3 firmwarebefore milanpi-sp3_1.0.0.4
• amd epyc 7301 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7302 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7302p firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7313 firmwarebefore milanpi-sp3_1.0.0.4
• amd epyc 7313p firmwarebefore milanpi-sp3_1.0.0.4
• amd epyc 7343 firmwarebefore milanpi-sp3_1.0.0.4
• amd epyc 7351 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7351p firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 7352 firmwarebefore romepi-sp3_1.0.0.c
• amd epyc 7371 firmwarebefore naplespi-sp3_1.0.0.g
• amd epyc 73f3 firmwarebefore milanpi-sp3_1.0.0.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (AMD). Independent of NVD's CPE analysis and usually ahead of it.

• AMD 1st Gen AMD EPYC™

  • unspecified and later · before NaplesPI-SP3_1.0.0.Gaffected

• AMD 2nd Gen AMD EPYC™

  • unspecified and later · before RomePI-SP3_1.0.0.Caffected

• AMD 3rd Gen AMD EPYC™

  • unspecified and later · before MilanPI-SP3_1.0.0.4affected

Other highest-scoring records for the same primary product.

• CVE-2020-12944Insufficient validation of BIOS image length by ASP Firmware could lead to arbitrary code execution.
  31Monitor
• CVE-2021-26322Persistent platform private key may not be protected with a random IV leading to a potential “two time pad attack”.
  30Monitor
• CVE-2021-26321Insufficient ID command validation in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP.
  22Monitor
• CVE-2021-26329AMD System Management Unit (SMU) may experience an integer overflow when an invalid length is provided which may result in a potential loss
  22Monitor
• CVE-2021-26312Failure to flush the Translation Lookaside Buffer (TLB) of the I/O memory management unit (IOMMU) may lead an IO device to write to memory i
  22Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {2  // Left empty for the test environment3}

1val client = OkHttpClient.Builder()2  .certificatePinner(3    CertificatePinner.Builder()4      .add("api.sirius.example", "sha256/…")5      .build()6  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.