Snapshot signature not including HeadID will allow replay attacks

{
  "id": "11fd99b1c69f3661a2de67f2537905ce2de69b7f945b7f49051d519909beb381",
  "url": "https://osv.dev/vulnerability/CVE-2023-42806",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Snapshot signature not including HeadID will allow replay attacks",
    "summary": "Hydra is the layer-two scalability solution for Cardano. Prior to version 0.13.0, not signing and verifying `$\\mathsf{cid}$` allows an attacker (which must be a participant of this head) to use a snapshot from an old head instance with the same participants to close the head or contest the state with it. This can lead to an incorrect distribution of value (= value extraction attack; hard, but possible) or prevent the head to finalize because the value available is not consistent with the closed utxo state (= denial of service; easy). A patch is planned for version 0.13.0. As a workaround, rotate keys between heads so not to re-use keys and not result in the same multi-signature participants.",
    "evidence": "osv:CVE-2023-42806",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2023-42806",
      "aliases": [
        "CVE-2023-42806",
        "GHSA-gr36-mc6v-72qq"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cardano-scaling/hydra",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "9f1027e0fdff6765f5233f19c4639fdaa3558bfa"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.13.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:iohk:hydra:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.13.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.12.0",
            "0.11.0",
            "0.10.0",
            "0.9.0",
            "0.8.1",
            "0.8.0",
            "0.7.0",
            "0.6.0",
            "0.5.0",
            "0.4.0",
            "plutus-merkle-tree-1.0.0",
            "plutus-cbor-1.0.0",
            "0.3.0",
            "0.2.0",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-42806.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.215200872Z",
      "provider": "osv",
      "references": [
        "https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/HeadLogic.hs#L357",
        "https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/Snapshot.hs#L50-L54",
        "https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-plutus/src/Hydra/Contract/Head.hs#L583-L599",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/42xxx/CVE-2023-42806.json",
        "https://github.com/input-output-hk/hydra/security/advisories/GHSA-gr36-mc6v-72qq",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-42806"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-347"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/42xxx/CVE-2023-42806.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-42806",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517394,
  "published_at": "2023-09-21T16:45:34.742+00:00"
}