New to CAPEC? Start Here
Home > CAPEC List > CAPEC-273: HTTP Response Smuggling (Version 3.5)  

CAPEC-273: HTTP Response Smuggling

Attack Pattern ID: 273
Abstraction: Detailed
Status: Draft
Presentation Filter:
+ Description
An attacker injects content into a server response that is interpreted differently by intermediaries than it is by the target browser. To do this, it takes advantage of inconsistent or incorrect interpretations of the HTTP protocol by various applications. For example, it might use different block terminating characters (CR or LF alone), adding duplicate header fields that browsers interpret as belonging to separate responses, or other techniques. Consequences of this attack can include response-splitting, cross-site scripting, apparent defacement of targeted sites, cache poisoning, or similar actions.
+ Typical Severity


+ Relationships
Section HelpThis table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
ChildOfStandard Attack PatternStandard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.220Client-Server Protocol Manipulation
PeerOfDetailed Attack PatternDetailed Attack Pattern - A detailed level attack pattern in CAPEC provides a low level of detail, typically leveraging a specific technique and targeting a specific technology, and expresses a complete execution flow. Detailed attack patterns are more specific than meta attack patterns and standard attack patterns and often require a specific protection mechanism to mitigate actual attacks. A detailed level attack pattern often will leverage a number of different standard level attack patterns chained together to accomplish a goal.33HTTP Request Smuggling
Section HelpThis table shows the views that this attack pattern belongs to and top level categories within that view.
+ Prerequisites
The targeted server must allow the attacker to insert content that will appear in the server's response.
+ Resources Required
None: No specialized resources are required to execute this type of attack.
+ Mitigations
Design: Employ strict adherence to interpretations of HTTP messages wherever possible.
Implementation: Encode header information provided by user input so that user-supplied content is not interpreted by intermediaries.
+ Taxonomy Mappings
Relevant to the WASC taxonomy mapping
Entry IDEntry Name
27HTTP Response Smuggling
+ References
[REF-117] "HTTP Response Smuggling". Beyond Security. <>.
+ Content History
Submission DateSubmitterOrganization
2014-06-23CAPEC Content TeamThe MITRE Corporation
Modification DateModifierOrganization
2017-08-04CAPEC Content TeamThe MITRE Corporation
Updated Related_Attack_Patterns, Resources_Required
2018-07-31CAPEC Content TeamThe MITRE Corporation
Updated References
2020-12-17CAPEC Content TeamThe MITRE Corporation
Updated Taxonomy_Mappings
More information is available — Please select a different filter.
Page Last Updated or Reviewed: December 17, 2020