Security advisory

{
  "id": "02b218b8055c7517073656aabdff9d18899861fcb93935688bed4f89cce00937",
  "url": "https://osv.dev/vulnerability/CVE-2021-23351",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-23351",
    "summary": "The package github.com/pires/go-proxyproto before 0.5.0 are vulnerable to Denial of Service (DoS) via the parseVersion1() function. The reader in this package is a default bufio.Reader wrapping a net.Conn. It will read from the connection until it finds a newline. Since no limits are implemented in the code, a deliberately malformed V1 header could be used to exhaust memory in a server process using this code - and create a DoS. This can be exploited by sending a stream starting with PROXY and continuing to send data (which does not contain a newline) until the target stops acknowledging. The risk here is small, because only trusted sources should be allowed to send proxy protocol headers.",
    "evidence": "osv:CVE-2021-23351",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-23351",
      "aliases": [
        "CVE-2021-23351",
        "GHSA-fqh4-rh59-xhvf",
        "SNYK-GOLANG-GITHUBCOMPIRESGOPROXYPROTO-1081577"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pires/go-proxyproto",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7f48261db810703d173f27f3309a808cc2b49b8b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:go-proxyproto_project:go-proxyproto:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.5.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7f48261db810703d173f27f3309a808cc2b49b8b"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.4.2",
            "v0.4.1",
            "v0.4.0",
            "v0.3.3",
            "v0.3.2",
            "v0.3.1",
            "v0.3.0",
            "v0.2.0",
            "v0.1.3",
            "0.1.2",
            "0.1.1",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-23351.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:32.439219211Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4BNVGJMVI3ZTZ675EFPUHPGXCKCGSX46/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/C36IBVOZXRTWM7MGTRUTOM56P5RR74VU/",
        "https://github.com/pires/go-proxyproto/issues/69",
        "https://snyk.io/vuln/SNYK-GOLANG-GITHUBCOMPIRESGOPROXYPROTO-1081577",
        "https://github.com/pires/go-proxyproto/commit/7f48261db810703d173f27f3309a808cc2b49b8b",
        "https://github.com/pires/go-proxyproto/pull/71"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "33"
                  },
                  {
                    "last_affected": "33"
                  },
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-23351",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385516,
  "published_at": "2021-03-08T05:15:12.593+00:00"
}