Security advisory

{
  "id": "cf2f0648308a158a8fdee6c2d3d57a4b69c8114dc1d448193603716eb9527d5a",
  "url": "https://osv.dev/vulnerability/CVE-2021-4188",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-4188",
    "summary": "mruby is vulnerable to NULL Pointer Dereference",
    "evidence": "osv:CVE-2021-4188",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-4188",
      "aliases": [
        "CVE-2021-4188"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mruby/mruby",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "0f45836b5954accf508f333f932741b925214471"
                },
                {
                  "fixed": "27d1e0132a0804581dca28df042e7047fd27eaa8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mruby:mruby:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "3.0.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "27d1e0132a0804581dca28df042e7047fd27eaa8"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.0.0",
            "3.0.0-rc",
            "3.0.0-preview",
            "1.2.0",
            "1.1.0",
            "1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4188.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-4188-9967f21e",
                "digest": {
                  "length": 890,
                  "function_hash": "37954158918689870791588392275949326726"
                },
                "source": "https://github.com/mruby/mruby/commit/27d1e0132a0804581dca28df042e7047fd27eaa8",
                "target": {
                  "file": "src/array.c",
                  "function": "mrb_ary_shift_m"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-4188-ec0cc330",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
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                },
                "source": "https://github.com/mruby/mruby/commit/27d1e0132a0804581dca28df042e7047fd27eaa8",
                "target": {
                  "file": "src/array.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T14:06:43Z"
          }
        }
      ],
      "modified": "2026-10-20T14:06:43.856067948Z",
      "provider": "osv",
      "references": [
        "https://github.com/mruby/mruby/commit/27d1e0132a0804581dca28df042e7047fd27eaa8",
        "https://huntr.dev/bounties/78533fb9-f3e0-47c2-86dc-d1f96d5bea28"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-4188",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388565,
  "published_at": "2021-12-30T07:15:06.527+00:00"
}