Security advisory

{
  "id": "22fb4846884134c5b438a3e9af7d749f3fa422f67f6d32b5f7b4cc4392df4978",
  "url": "https://osv.dev/vulnerability/CVE-2021-28683",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-28683",
    "summary": "An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable NULL pointer dereference and crash in TLS when an unknown TLS alert code is received.",
    "evidence": "osv:CVE-2021-28683",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-28683",
      "aliases": [
        "BIT-envoy-2021-28683",
        "CVE-2021-28683"
      ],
      "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/envoyproxy/envoy",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e98e41a8e168af7acae8079fc0cd68155f699aa3"
                },
                {
                  "last_affected": "d6a4496e712d7a2335b26e2f76210d5904002c26"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:envoyproxy:envoy:1.16.2:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.16.2"
                      },
                      {
                        "last_affected": "1.16.2"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:envoyproxy:envoy:1.17.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.17.1"
                      },
                      {
                        "last_affected": "1.17.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.16.2",
            "1.17.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-28683.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:36.358211196Z",
      "provider": "osv",
      "references": [
        "https://blog.envoyproxy.io",
        "https://github.com/envoyproxy/envoy/releases",
        "https://github.com/envoyproxy/envoy/security/advisories/GHSA-r22g-5f3x-xjgg",
        "https://github.com/envoyproxy/envoy/security/advisories/GHSA-xw4q-6pj2-5gfg"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-28683",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385709,
  "published_at": "2021-05-20T17:15:07.713+00:00"
}