cve.bz

CAPEC-319

IP (DF) 'Don't Fragment Bit' Echoing Probe

Low severityMedium likelihoodDetailed pattern

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.

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Show the promptExplain the attack pattern CAPEC-319: IP (DF) 'Don't Fragment Bit' Echoing Probe: how it unfolds, what it needs and how to prevent and detect it in my systems. Use https://capec.mitre.org/data/definitions/319.html and https://cve.bz/cve/capec/319?via=ask-ai-copy, which lists recent CVEs with the weaknesses it exploits. Cite the sources.

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Consequences

What a successful attack can lead to
ImpactAffectsNote
Read DataConfidentiality
Bypass Protection Mechanism, Hide ActivitiesConfidentiality, Access Control, Authorization

Weaknesses it exploits

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Recent CVEs with these weaknesses

  1. 4.3CVE-2026-124944

    Information disclosure in the Marionette component. This vulnerability was fixed in Firefox 160.

  2. 4.3CVE-2026-124941

    Information disclosure in the Security: RLBox component. This vulnerability was fixed in Firefox 160 and Firefox ESR 153.7.

  3. 4.3CVE-2026-124930

    Information disclosure in the Address Bar component. This vulnerability was fixed in Firefox 160 and Firefox ESR 153.7.

  4. 4.3CVE-2026-124929

    Information disclosure in the Layout: Form Controls component. This vulnerability was fixed in Firefox 160 and Firefox ESR 153.7.

  5. 4.3CVE-2026-124925

    Information disclosure in the Layout component. This vulnerability was fixed in Firefox 160.

  6. 4.3CVE-2026-124909

    Information disclosure in the Private Browsing component. This vulnerability was fixed in Firefox 160 and Firefox ESR 153.7.

  7. 5.3CVE-2026-96769

    The Extend B2B - Companies and Users Management for WooCommerce plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.1.4 via the register_company_api. This makes it possible for unaut…

  8. 7.5CVE-2026-63644

    bird-lg-go is a BIRD looking glass in Go. Prior to version 1.4.7, unsanitized input path enables arbitrary local file read, allowing an unauthenticated remote attacker to read sensitive files such as /etc/shadow and /root/.bash_history. Th…

The newest records naming one of them. Each weakness's page lists them all.

Part of

MITRE's words, unchanged: CAPEC-319 at MITRE. CAPEC is Copyright © 2007–2026, The MITRE Corporation, used under the CAPEC terms of use: “The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use Common Attack Pattern Enumeration and Classification (CAPEC™) for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE’s copyright designation and this license in any such copy.” CAPEC and the CAPEC logo are trademarks of The MITRE Corporation. Credits. All attack patterns.