fkie_cve-2021-36647
Vulnerability from fkie_nvd
Published
2023-01-17 21:15
Modified
2025-11-03 20:15
Severity ?
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Summary
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.
References
cve@mitre.orghttps://github.com/ARMmbed/mbedtls/releases/Third Party Advisory
cve@mitre.orghttps://kouzili.com/Load-Step.pdfThird Party Advisory
cve@mitre.orghttps://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/ARMmbed/mbedtls/releases/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://kouzili.com/Load-Step.pdfThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html
af854a3a-2127-422b-91ae-364da2661108https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1Vendor Advisory
Impacted products
Vendor Product Version
arm mbed_tls *
arm mbed_tls *
arm mbed_tls *


To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E24E3CA8-CBFE-4C75-A3C0-1B0D8C3B694B",
              "versionEndExcluding": "2.16.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "32B8405B-52A8-485A-85D2-D696626DBE19",
              "versionEndExcluding": "2.27.0",
              "versionStartIncluding": "2.17.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "539125FA-10D5-41EF-B5D7-93B809231A33",
              "versionEndExcluding": "3.0.0",
              "versionStartIncluding": "2.28.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "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 criptogr\u00e1fico roto o riesgoso en la funci\u00f3n 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 informaci\u00f3n 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."
    }
  ],
  "id": "CVE-2021-36647",
  "lastModified": "2025-11-03T20:15:49.343",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      },
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ]
  },
  "published": "2023-01-17T21:15:10.880",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/ARMmbed/mbedtls/releases/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://kouzili.com/Load-Step.pdf"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/ARMmbed/mbedtls/releases/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://kouzili.com/Load-Step.pdf"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "https://lists.debian.org/debian-lts-announce/2025/06/msg00034.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-327"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-327"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}


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