GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration
ubuntu-cve-2023-6237
Vulnerability from osv_ubuntu
Published
2024-01-15 00:00
Modified
2026-04-22 07:45
Summary
Details

Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.

Severity
5.9 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
low
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.14"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.14"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.14?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.2-0ubuntu1.14"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.1l-1ubuntu1",
        "3.0.0-1ubuntu1",
        "3.0.1-0ubuntu1",
        "3.0.2-0ubuntu1",
        "3.0.2-0ubuntu1.1",
        "3.0.2-0ubuntu1.2",
        "3.0.2-0ubuntu1.4",
        "3.0.2-0ubuntu1.5",
        "3.0.2-0ubuntu1.6",
        "3.0.2-0ubuntu1.7",
        "3.0.2-0ubuntu1.8",
        "3.0.2-0ubuntu1.9",
        "3.0.2-0ubuntu1.10",
        "3.0.2-0ubuntu1.12",
        "3.0.2-0ubuntu1.13"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnode72",
            "binary_version": "12.22.9~dfsg-1ubuntu3.6+esm2"
          },
          {
            "binary_name": "nodejs",
            "binary_version": "12.22.9~dfsg-1ubuntu3.6+esm2"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "nodejs",
        "purl": "pkg:deb/ubuntu/nodejs@12.22.9~dfsg-1ubuntu3.6+esm2?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "12.22.5~dfsg-5ubuntu1",
        "12.22.7~dfsg-2ubuntu1",
        "12.22.7~dfsg-2ubuntu3",
        "12.22.9~dfsg-1ubuntu2",
        "12.22.9~dfsg-1ubuntu3",
        "12.22.9~dfsg-1ubuntu3.1",
        "12.22.9~dfsg-1ubuntu3.2",
        "12.22.9~dfsg-1ubuntu3.3",
        "12.22.9~dfsg-1ubuntu3.4",
        "12.22.9~dfsg-1ubuntu3.5",
        "12.22.9~dfsg-1ubuntu3.6",
        "12.22.9~dfsg-1ubuntu3.6+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.12+Fips1"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.12+Fips1"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-preview:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.12+Fips1?arch=source\u0026distro=fips-preview/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.2-0ubuntu1.10+Fips1",
        "3.0.2-0ubuntu1.12+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.14+Fips1"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.14+Fips1"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.14+Fips1?arch=source\u0026distro=fips-updates/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.2-0ubuntu1.14+Fips1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.2-0ubuntu1.10+Fips1",
        "3.0.2-0ubuntu1.12+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "efi-shell-aa64",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "efi-shell-arm",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "efi-shell-ia32",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "efi-shell-x64",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "ovmf",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "ovmf-ia32",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "qemu-efi-arm",
            "binary_version": "2024.02-2ubuntu0.6"
          },
          {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2024.02-2ubuntu0.6"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "edk2",
        "purl": "pkg:deb/ubuntu/edk2@2024.02-2ubuntu0.6?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2024.02-2ubuntu0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2023.05-2",
        "2023.11-2",
        "2023.11-3",
        "2023.11-4",
        "2023.11-5",
        "2023.11-6",
        "2023.11-8",
        "2024.02-1",
        "2024.02-2",
        "2024.02-2ubuntu0.1",
        "2024.02-2ubuntu0.3",
        "2024.02-2ubuntu0.4",
        "2024.02-2ubuntu0.5"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.10-1ubuntu4"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.10-1ubuntu4"
          }
        ],
        "priority_reason": "Upstream OpenSSL project has rated this as low severity"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.10-1ubuntu4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.10-1ubuntu4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.10-1ubuntu2",
        "3.0.10-1ubuntu2.1",
        "3.0.10-1ubuntu3"
      ]
    }
  ],
  "aliases": [],
  "details": "Issue summary: Checking excessively long invalid RSA public keys may take a long time. Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service. When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time. An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack. The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the \u0027-pubin\u0027 and \u0027-check\u0027 options on untrusted data. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.",
  "id": "UBUNTU-CVE-2023-6237",
  "modified": "2026-04-22T07:45:09Z",
  "published": "2024-01-15T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2023-6237"
    },
    {
      "type": "REPORT",
      "url": "https://www.openssl.org/news/secadv/20240115.txt"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-6622-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-6237"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-7894-1"
    }
  ],
  "related": [
    "USN-6622-1",
    "USN-7894-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "low",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2023-6237"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.