FKIE_CVE-2026-31790

Vulnerability from fkie_nvd - Published: 2026-04-07 22:16 - Updated: 2026-07-24 23:10
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.
References
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/001e01db3e996e13ffc72386fe79d03a6683b5acPatch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/abd8b2eec7e3f3fda60ecfb68498b246b52af482Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/b922e24e5b23ffb9cb9e14cadff23d91e9f7e406Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/d5f8e71cd0a54e961d0c3b174348f8308486f790Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/eed200f58cd8645ed77e46b7e9f764e284df379ePatch
openssl-security@openssl.orghttps://openssl-library.org/news/secadv/20260407.txtVendor Advisory
0b142b55-0307-4c5a-b3c9-f314f3fb7c5ehttps://cert-portal.siemens.com/productcert/html/ssa-032379.html
Impacted products
Vendor Product Version
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "OpenSSL",
          "vendor": "OpenSSL",
          "versions": [
            {
              "lessThan": "3.6.2",
              "status": "affected",
              "version": "3.6.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.5.6",
              "status": "affected",
              "version": "3.5.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.4.5",
              "status": "affected",
              "version": "3.4.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.3.7",
              "status": "affected",
              "version": "3.3.0",
              "versionType": "semver"
            },
            {
              "lessThan": "3.0.20",
              "status": "affected",
              "version": "3.0.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "openssl-security@openssl.org"
    },
    {
      "affectedData": [
        {
          "defaultStatus": "unknown",
          "product": "SIMATIC CN 4100",
          "vendor": "Siemens",
          "versions": [
            {
              "lessThan": "V5.0",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B28A8143-89A4-4332-A1F8-A65FB5AA829F",
              "versionEndExcluding": "3.0.20",
              "versionStartIncluding": "3.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "CF303B21-D9BF-461D-B7B0-A3FE1D557A9F",
              "versionEndExcluding": "3.3.7",
              "versionStartIncluding": "3.3.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DCCE43D0-8F17-475D-9EE6-842F758A9905",
              "versionEndExcluding": "3.4.5",
              "versionStartIncluding": "3.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F6BC0271-444D-4597-BF05-DC60034EAA49",
              "versionEndExcluding": "3.5.6",
              "versionStartIncluding": "3.5.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "4A9E621D-29D8-418A-BF37-BED333C14507",
              "versionEndExcluding": "3.6.2",
              "versionStartIncluding": "3.6.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Issue summary: Applications using RSASVE key encapsulation to establish\na secret encryption key can send contents of an uninitialized memory buffer to\na malicious peer.\n\nImpact summary: The uninitialized buffer might contain sensitive data from the\nprevious execution of the application process which leads to sensitive data\nleakage to an attacker.\n\nRSA_public_encrypt() returns the number of bytes written on success and -1\non error. The affected code tests only whether the return value is non-zero.\nAs a result, if RSA encryption fails, encapsulation can still return success to\nthe caller, set the output lengths, and leave the caller to use the contents of\nthe ciphertext buffer as if a valid KEM ciphertext had been produced.\n\nIf applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an\nattacker-supplied invalid RSA public key without first validating that key,\nthen this may cause stale or uninitialized contents of the caller-provided\nciphertext buffer to be disclosed to the attacker in place of the KEM\nciphertext.\n\nAs a workaround calling EVP_PKEY_public_check() or\nEVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate\nthe issue.\n\nThe FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue."
    },
    {
      "lang": "es",
      "value": "Resumen del problema: Las aplicaciones que utilizan la encapsulaci\u00f3n de clave RSASVE para establecer una clave de cifrado secreta pueden enviar el contenido de un b\u00fafer de memoria no inicializado a un par malicioso.\n\nResumen del impacto: El b\u00fafer no inicializado podr\u00eda contener datos sensibles de la ejecuci\u00f3n anterior del proceso de la aplicaci\u00f3n, lo que lleva a la fuga de datos sensibles a un atacante.\n\nRSA_public_encrypt() devuelve el n\u00famero de bytes escritos en caso de \u00e9xito y -1 en caso de error. El c\u00f3digo afectado solo prueba si el valor de retorno no es cero. Como resultado, si el cifrado RSA falla, la encapsulaci\u00f3n a\u00fan puede devolver \u00e9xito al llamador, establecer las longitudes de salida y dejar que el llamador use el contenido del b\u00fafer de texto cifrado como si se hubiera producido un texto cifrado KEM v\u00e1lido.\n\nSi las aplicaciones usan EVP_PKEY_encapsulate() con RSA/RSASVE en una clave p\u00fablica RSA inv\u00e1lida proporcionada por un atacante sin validar primero esa clave, entonces esto puede causar que el contenido obsoleto o no inicializado del b\u00fafer de texto cifrado proporcionado por el llamador sea divulgado al atacante en lugar del texto cifrado KEM.\n\nComo soluci\u00f3n alternativa, llamar a EVP_PKEY_public_check() o EVP_PKEY_public_check_quick() antes de EVP_PKEY_encapsulate() mitigar\u00e1 el problema.\n\nLos m\u00f3dulos FIPS en 3.6, 3.5, 3.4, 3.3, 3.1 y 3.0 se ven afectados por este problema."
    }
  ],
  "id": "CVE-2026-31790",
  "lastModified": "2026-07-24T23:10:00.563",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-31790",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-04-08T14:32:04.700201Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-04-07T22:16:21.770",
  "references": [
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/openssl/openssl/commit/001e01db3e996e13ffc72386fe79d03a6683b5ac"
    },
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/openssl/openssl/commit/abd8b2eec7e3f3fda60ecfb68498b246b52af482"
    },
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/openssl/openssl/commit/b922e24e5b23ffb9cb9e14cadff23d91e9f7e406"
    },
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/openssl/openssl/commit/d5f8e71cd0a54e961d0c3b174348f8308486f790"
    },
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/openssl/openssl/commit/eed200f58cd8645ed77e46b7e9f764e284df379e"
    },
    {
      "source": "openssl-security@openssl.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://openssl-library.org/news/secadv/20260407.txt"
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html"
    }
  ],
  "sourceIdentifier": "openssl-security@openssl.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-754"
        }
      ],
      "source": "openssl-security@openssl.org",
      "type": "Secondary"
    }
  ]
}



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