{
  "node_id": "mitre-capec-capec-319-ip-df-don-t-fragment-bit-echoing-probe",
  "title": "MITRE CAPEC-319: IP (DF) 'Don't Fragment Bit' Echoing Probe (Detailed Attack Pattern - Low Severity)",
  "domain": "Cybersecurity",
  "version": "1.0.0",
  "last_updated": "2026-05-25",
  "bluf": "MITRE CAPEC-319 (IP (DF) 'Don't Fragment Bit' Echoing Probe) is a detailed-level attack pattern in the MITRE Common Attack Pattern Enumeration and Classification. This OS fingerprinting probe tests to determine if the remote host echoes back the IP 'DF' (Don't Fragment) bit in a response packet. An attacker sends a UDP datagram with the DF bit set to a closed port on the remote host to observe whether the 'DF' bit is set in the response packet. Some operating systems will echo the bit in the ICMP error message while others will zero out the bit in the response packet. Likelihood of attack: Medium. Typical severity: Low. Maps to weaknesses CWE-200.",
  "paywall": {
    "status": "LOCKED",
    "unlock_cost_usd": "0.01",
    "skyfire_id": "41779894-ece2-4163-9761-b3b1b76e19b0"
  },
  "crosswalks": {
    "_available_keys": [
      "nist_framework",
      "iso_standard",
      "industry_mapping",
      "mitre_attack"
    ],
    "_note": "Full crosswalk values included in vault response"
  },
  "dependencies": [
    "nist-sp-800-53-r5",
    "iso-27001-2022",
    "cis-controls-v8",
    "owasp-asvs-l2"
  ],
  "primary_citations_count": 7
}