Security advisory

{
  "id": "5b172c9ef1c023181331924048d1e2e93800efc74dc5a7a8950c7e8c7a757b43",
  "url": "https://osv.dev/vulnerability/CVE-2021-38173",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-38173",
    "summary": "Btrbk before 0.31.2 allows command execution because of the mishandling of remote hosts filtering SSH commands using ssh_filter_btrbk.sh in authorized_keys.",
    "evidence": "osv:CVE-2021-38173",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-38173",
      "aliases": [
        "CVE-2021-38173"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/digint/btrbk",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "e8622fc6be3fe2cdeedf80bb084b8b442fae2365"
                },
                {
                  "fixed": "58212de771c381cd4fa05625927080bf264e9584"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:digint:btrbk:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.31.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "58212de771c381cd4fa05625927080bf264e9584"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.31.1",
            "v0.31.0",
            "v0.30.0",
            "v0.29.1",
            "v0.29.0",
            "v0.28.3",
            "v0.28.2",
            "v0.28.1",
            "v0.28.0",
            "v0.27.2",
            "v0.27.1",
            "v0.27.0",
            "v0.26.1",
            "v0.26.0",
            "v0.25.1",
            "v0.25.0",
            "v0.24.0",
            "v0.23.3",
            "v0.23.2",
            "v0.23.1",
            "v0.23.0",
            "v0.23.0-rc1",
            "v0.22.2",
            "v0.22.1",
            "v0.22.0",
            "v0.21.0",
            "v0.20.0",
            "v0.19.3",
            "v0.19.2",
            "v0.19.1",
            "v0.19.0",
            "v0.18.0",
            "v0.17.1",
            "v0.17.0",
            "v0.16",
            "v0.15",
            "v0.14",
            "v0.13",
            "v0.12",
            "v0.11",
            "v0.10"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-38173.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:51.554748055Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BP2T32JMENJFRP2HWXR7FTTZVRTTPECL/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LM7GLTUN5YS4KE2RNBX732EAMVVGNEX3/",
        "https://github.com/digint/btrbk/blob/master/ChangeLog",
        "https://lists.debian.org/debian-lts-announce/2021/09/msg00002.html",
        "https://github.com/digint/btrbk/commit/58212de771c381cd4fa05625927080bf264e9584"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  },
                  {
                    "introduced": "35"
                  },
                  {
                    "last_affected": "35"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-38173",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386292,
  "published_at": "2021-08-07T19:15:06.997+00:00"
}