The product does not sufficiently monitor or control transmitted network traffic volume, so that an actor can cause the product to transmit more traffic than should be allowed for that actor.
In the absence of a policy to restrict asymmetric resource consumption, the application or system cannot distinguish between legitimate transmissions and traffic intended to serve as an amplifying attack on target systems. Systems can often be configured to restrict the amount of traffic sent out on behalf of a client, based on the client's origin or access level. This is usually defined in a resource allocation policy. In the absence of a mechanism to keep track of transmissions, the system or application can be easily abused to transmit asymmetrically greater traffic than the request or client should be permitted to.

Resultant

Operation

Architecture and Design
If the application uses UDP, then it could potentially be subject to spoofing attacks that use the inherent weaknesses of UDP to perform traffic amplification, although this problem can exist in other protocols or contexts.

Implementation

Availability
DoS: Amplification
DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
DoS: Resource Consumption (Other)
System resources can be quickly consumed leading to poor application performance or system crash. This may affect network performance and could be used to attack other systems and applications relying on network performance.

Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Architecture and Design
Separation of Privilege
An application must make network resources available to a client commensurate with the client's access level.

Policy
Define a clear policy for network resource allocation and consumption.

Implementation
An application must, at all times, keep track of network resources and meter their usage appropriately.

This code listens on a port for DNS requests and sends the result to the requesting address.

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)sock.bind( (UDP_IP,UDP_PORT) )while true:
data = sock.recvfrom(1024)if not data:break
(requestIP, nameToResolve) = parseUDPpacket(data)record = resolveName(nameToResolve)sendResponse(requestIP,record)

This code sends a DNS record to a requesting IP address. UDP allows the source IP address to be easily changed ('spoofed'), thus allowing an attacker to redirect responses to a target, which may be then be overwhelmed by the network traffic.

CVE-1999-0513
Classic "Smurf" attack, using spoofed ICMP packets to broadcast addresses.
https://www.cve.org/CVERecord?id=CVE-1999-0513

CVE-1999-1379
DNS query with spoofed source address causes more traffic to be returned to spoofed address than was sent by the attacker.
https://www.cve.org/CVERecord?id=CVE-1999-1379

CVE-2000-0041
Large datagrams are sent in response to malformed datagrams.
https://www.cve.org/CVERecord?id=CVE-2000-0041

CVE-1999-1066
Game server sends a large amount.
https://www.cve.org/CVERecord?id=CVE-1999-1066

CVE-2013-5211
composite: NTP feature generates large responses (high amplification factor) with spoofed UDP source addresses.
https://www.cve.org/CVERecord?id=CVE-2013-5211

Network Amplification

Allowed-with-Review
This CWE entry is a Class, but it does not have Base-level children.
This entry is classified in a part of CWE's hierarchy that does not have sufficiently low-level coverage, which might reflect a lack of classification-oriented weakness research in the software security community. Conduct careful root cause analysis to determine the original mistake that led to this weakness. If closer analysis reveals that this weakness is appropriate, then this might be the best available CWE to use for mapping. If no other option is available, then it is acceptable to map to this CWE.

This can be resultant from weaknesses that simplify spoofing attacks.
Network amplification, when performed with spoofing, is normally a multi-channel attack from attacker (acting as user) to amplifier, and amplifier to victim.

PLOVER
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Relationships, Other_Notes, Taxonomy_Mappings

CWE Content Team
MITRE
2008-10-14
updated Description, Enabling_Factors_for_Exploitation, Name, Other_Notes, Theoretical_Notes

CWE Content Team
MITRE
2010-06-21
updated Other_Notes, Relationship_Notes

CWE Content Team
MITRE
2011-03-29
updated Demonstrative_Examples

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated Common_Consequences, Relationships

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2014-02-18
updated Demonstrative_Examples, Observed_Examples, Relationships

CWE Content Team
MITRE
2014-07-30
updated Relationships

CWE Content Team
MITRE
2017-11-08
updated Applicable_Platforms, Enabling_Factors_for_Exploitation, Modes_of_Introduction

CWE Content Team
MITRE
2019-06-20
updated Type

CWE Content Team
MITRE
2020-02-24
updated Relationships

CWE Content Team
MITRE
2022-04-28
updated Relationships

CWE Content Team
MITRE
2023-01-31
updated Description

CWE Content Team
MITRE
2023-04-27
updated Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-04-03
4.17
2025-04-03
updated Mapping_Notes

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Detection_Factors, Weakness_Ordinalities

Network Amplification