{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "ckb"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.40.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-08-02T21:53:41Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "In the ckb sync protocol, SyncState maintains a HashMap called \u0027misbehavior\u0027 that keeps a score of a peer\u0027s violations of the protocol. This HashMap is keyed to PeerIndex (an alias for SessionId), and entries are never removed from it. SessionId is an integer that increases monotonically with every new connection.\n\nA remote attacker can manipulate this HashMap to grow forever, resulting in degraded performance and ultimately a panic on allocation failure or being killed by the OS, depending on the platform.\n\nThis is a critical severity security bug. It could be exploited to create a targeted or network-wide denial of service, to reduce the hash power of the network as part of a 51% attack, and perhaps in other creative ways.\n\nAn attack is trivial:\n\n1. connect to another node\n2. send an invalid sync protocol request, such as `SendHeaders` for non-consecutive blocks\n3. disconnect\n4. repeat",
  "id": "GHSA-48vq-8jqv-gm6f",
  "modified": "2021-08-02T21:53:41Z",
  "published": "2021-08-25T21:01:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nervosnetwork/ckb/security/advisories/GHSA-48vq-8jqv-gm6f"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2021-0108.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Remote memory exhaustion in ckb"
}