{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "pocketmine/pocketmine-mp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.15.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-11-11T21:38:07Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\nSpecially crafted `InventoryTransactionPacket`s sent by malicious clients were able to exploit the behaviour of `InventoryTransaction-\u003efindResultItem()` and cause it to take an abnormally long time to execute (causing an apparent server freeze).\n\nThe affected code is intended to compact conflicting `InventoryActions` which are in the same `InventoryTransaction` by flattening them into a single action. When multiple pathways to a result existed, the complexity of this flattening became exponential.\n\nThe problem was fixed by bailing when ambiguities are detected.\n\n**At the time of writing, this exploit is being used in the wild by attackers to deny service to servers.**\n\n### Patches\nUpgrade to 3.15.4 or newer.\n\n### Workarounds\nNo practical workarounds are possible, short of backporting the fix or implementing checks in a plugin listening to `DataPacketReceiveEvent`.\n\n### References\nc368ebb5e74632bc622534b37cd1447b97281e20\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [team@pmmp.io](mailto:team@pmmp.io)",
  "id": "GHSA-8jq6-w5cg-wm45",
  "modified": "2020-11-11T21:38:07Z",
  "published": "2020-11-11T21:38:18Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-8jq6-w5cg-wm45"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Exploitable inventory component chaining in PocketMine-MP"
}