CAPEC-495
UDP Fragmentation
An attacker may execute a UDP Fragmentation attack against a target server in an attempt to consume resources such as bandwidth and CPU. IP fragmentation occurs when an IP datagram is larger than the MTU of the route the datagram has to traverse. Typically the attacker will use large UDP packets over 1500 bytes of data which forces fragmentation as ethernet MTU is 1500 bytes. This attack is a variation on a typical UDP flood but it enables more network bandwidth to be consumed with fewer packets. Additionally it has the potential to consume server CPU resources and fill memory buffers associated with the processing and reassembling of fragmented packets.
On this page
Ask an AI about this attack pattern
Show the prompt
Explain the attack pattern CAPEC-495: UDP Fragmentation: how it unfolds, what it needs and how to prevent and detect it in my systems. Use https://capec.mitre.org/data/definitions/495.html and https://cve.bz/cve/capec/495?via=ask-ai-copy, which lists recent CVEs with the weaknesses it exploits. Cite the sources.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this attack pattern's id and public links.
Prerequisites
This type of an attack requires the attacker to be able to generate fragmented IP traffic containing crafted data.
Mitigations
This attack may be mitigated by changing default cache sizes to be larger at the OS level. Additionally rules can be enforced to prune the cache with shorter timeouts for packet reassembly as the cache nears capacity.
Weaknesses it exploits
- CWE-404 Improper Resource Shutdown or Release
- CWE-770 Allocation of Resources Without Limits or Throttling
Recent CVEs with these weaknesses
- –CVE-2026-86531
The embedded OpenEJB HTTP server does not limit the size of incoming request bodies or of multipart requests, and does not remove the temporary files it creates for multipart parts. A remote unauthenticated attacker can cause excessive mem…
- 7.0CVE-2026-114359
Eclipse Kura downloads deployment packages (DPs) from a remote URL without any limit on the size of the data it receives. A malicious or compromised HTTP(S) server, or an attacker able to tamper with a plain-HTTP download, can stream an ar…
- 8.7CVE-2026-60040
An unauthenticated remote attacker can perform a DoS in the backends backup creation function. This can result in a total loss of availability.
- 8.7CVE-2026-123817
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the WebSocket reader retains one bytes object for each transport read while reassembling an incomplete frame. A malicious peer can split a fra…
- 6.8CVE-2026-125205
FFmpeg through 9.0.2 contains an unbounded memory allocation vulnerability in the av1_frame_merge bitstream filter that allows attackers to exhaust memory by never sending a temporal delimiter OBU. Attackers can supply a crafted .obu file …
- 5.7CVE-2026-125186
FFmpeg through 9.0.2 contains an uncontrolled resource consumption vulnerability in the dts2pts bitstream filter that allows attackers to exhaust CPU through unbounded per-packet POC node allocation. Attackers can supply a crafted H.264 pa…
- 6.8CVE-2026-125180
FFmpeg 8.1 through 9.0.2 contains a memory exhaustion vulnerability in the libavcodec/exif.c parser that allows attackers to amplify allocations by pointing many IFD entries at overlapping payloads. Attackers can embed a small crafted EXIF…
- 7.5CVE-2026-112322
clean_client() in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) restarts its scan from the head of the client list after each removal, resulting in quadratic CPU cost. Remote attackers can cause a denial of service (CPU consumptio…
The newest records naming one of them. Each weakness's page lists them all.
Related attack patterns
- Part of
- CAPEC-130 Excessive Allocation
MITRE's words, unchanged: CAPEC-495 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.