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CVE-2021-36647

Estado: ModificadaMedia (4.7)—

Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (2)

ARM — Mbed TLSTrustedfirmware — Mbed TLS

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2021-36647",
  "cveTags": [],
  "metrics": {
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        "ssvcData": {
          "id": "CVE-2021-36647",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
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          ],
          "version": "2.0.3",
          "timestamp": "2025-04-08T20:30:16.965859Z"
        }
      }
    ],
    "cvssMetricV31": [
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          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1
      },
      {
        "type": "Secondary",
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        "cvssData": {
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          "integrityImpact": "NONE",
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  "published": "2023-01-17T21:15:10.880",
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  "weaknesses": [
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  "descriptions": [
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      "lang": "en",
      "value": "Use of a Broken or Risky Cryptographic Algorithm in the function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all versions before 3.0.0, 2.27.0 or 2.16.11 allows attackers with access to precise enough timing and memory access information (typically an untrusted operating system attacking a secure enclave such as SGX or the TrustZone secure world) to recover the private keys used in RSA."
    },
    {
      "lang": "es",
      "value": "Uso de un algoritmo criptográfico roto o riesgoso en la función mbedtls_mpi_exp_mod() en lignum.c en Mbed TLS Mbed TLS todas las versiones anteriores a 3.0.0, 2.27.0 o 2.16.11 permite a los atacantes acceder a información de tiempo y acceso a memoria suficientemente precisa (normalmente un sistema operativo que no es de confianza que ataca un enclave seguro como SGX o el mundo seguro TrustZone) para recuperar las claves privadas utilizadas en RSA."
    }
  ],
  "lastModified": "2026-06-17T03:58:59.387",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}