Security advisory

{
  "id": "3175c67a2736aed30e5935a87a49fc6d625c948a40214bbdb06884c5df3ff8c5",
  "url": "https://osv.dev/vulnerability/CVE-2021-21374",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-21374",
    "summary": "Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, \"nimble refresh\" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.",
    "evidence": "osv:CVE-2021-21374",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-21374",
      "aliases": [
        "CVE-2021-21374",
        "GHSA-c2wm-v66h-xhxx"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nim-lang/nim",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ebc114c5266582dcaf5e323e0ec3d2b2a9f17063"
                },
                {
                  "introduced": "018ae963ba83934a68d815c3c1c44c06e8ec6178"
                },
                {
                  "fixed": "2ff517462bf8609b30e6134c96658aa7912b628a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.2.10"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.4.0"
                      },
                      {
                        "fixed": "1.4.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.2",
            "v1.2.8",
            "v1.4.0",
            "v1.2.6",
            "v1.2.4",
            "v1.2.2",
            "v1.2.0",
            "v1.0.0",
            "v0.20.0",
            "v0.19.0",
            "v0.18.0",
            "v0.17.2",
            "v0.17.0",
            "v0.16.0",
            "v0.15.2",
            "v0.14.2",
            "v0.15.0",
            "v0.14.0",
            "v0.13.0",
            "v0.12.0",
            "v0.11.2",
            "v0.11.0",
            "v0.10.2",
            "v0.9.4",
            "v0.9.2",
            "v0.9.0",
            "v0.8.14"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21374.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:28.377906750Z",
      "provider": "osv",
      "references": [
        "https://github.com/nim-lang/nimble/blob/master/changelog.markdown#0130",
        "https://github.com/nim-lang/security/security/advisories/GHSA-c2wm-v66h-xhxx",
        "https://github.com/nim-lang/Nim/pull/16940",
        "https://consensys.net/diligence/vulnerabilities/nim-insecure-ssl-tls-defaults-remote-code-execution/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-21374",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385414,
  "published_at": "2021-03-26T22:15:12.867+00:00"
}