Common Weakness Enumeration

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CWE-300: Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

Weakness ID: 300
Abstraction: Class
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The product does not adequately verify the identity of actors at both ends of a communication channel, or does not adequately ensure the integrity of the channel, in a way that allows the channel to be accessed or influenced by an actor that is not an endpoint.
+ Extended Description
In order to establish secure communication between two parties, it is often important to adequately verify the identity of entities at each end of the communication channel. Inadequate or inconsistent verification may result in insufficient or incorrect identification of either communicating entity. This can have negative consequences such as misplaced trust in the entity at the other end of the channel. An attacker can leverage this by interposing between the communicating entities and masquerading as the original entity. In the absence of sufficient verification of identity, such an attacker can eavesdrop and potentially modify the communication between the original entities.
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
+ Relevant to the view "Architectural Concepts" (CWE-1008)
MemberOfCategoryCategory1011Authorize Actors
+ Relevant to the view "Development Concepts" (CWE-699)
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

Architecture and DesignREALIZATION: This weakness is caused during implementation of an architectural security tactic.
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.


Class: Language-Independent (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

Access Control

Technical Impact: Read Application Data; Modify Application Data; Gain Privileges or Assume Identity

An attacker could pose as one of the entities and read or possibly modify the communication.
+ Demonstrative Examples

Example 1

In the Java snippet below, data is sent over an unencrypted channel to a remote server.

(bad code)
Example Language: Java 
Socket sock;
PrintWriter out;

try {
sock = new Socket(REMOTE_HOST, REMOTE_PORT);
out = new PrintWriter(echoSocket.getOutputStream(), true);
// Write data to remote host via socket output stream.



By eavesdropping on the communication channel or posing as the endpoint, an attacker would be able to read all of the transmitted data.

+ Observed Examples
chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing man-in-the-middle attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-561 (Dead Code) -> CWE-295 (Improper Certificate Validation) -> CWE-393 (Return of Wrong Status Code) -> CWE-300 (Channel Accessible by Non-Endpoint ('Man-in-the-Middle')).
+ Potential Mitigations

Phase: Implementation

Always fully authenticate both ends of any communications channel.

Phase: Architecture and Design

Adhere to the principle of complete mediation.

Phase: Implementation

A certificate binds an identity to a cryptographic key to authenticate a communicating party. Often, the certificate takes the encrypted form of the hash of the identity of the subject, the public key, and information such as time of issue or expiration using the issuer's private key. The certificate can be validated by deciphering the certificate with the issuer's public key. See also X.509 certificate signature chains and the PGP certification structure.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
+ Notes


The summary identifies multiple distinct possibilities, suggesting that this is a category that must be broken into more specific weaknesses.
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERMan-in-the-middle (MITM)
WASC32Routing Detour
CERT Java Secure CodingSEC06-JDo not rely on the default automatic signature verification provided by URLClassLoader and java.util.jar
+ References
[REF-244] M. Bishop. "Computer Security: Art and Science". Addison-Wesley. 2003.
+ Content History
Submission DateSubmitterOrganization
Modification DateModifierOrganization
2008-07-01Sean EidemillerCigital
added/updated demonstrative examples
2008-07-01Eric DalciCigital
updated Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Description, Maintenance_Notes, Relationships, Taxonomy_Mappings
2009-05-27CWE Content TeamMITRE
updated Name
2010-02-16CWE Content TeamMITRE
updated Taxonomy_Mappings
2010-12-13CWE Content TeamMITRE
updated Description
2011-06-01CWE Content TeamMITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11CWE Content TeamMITRE
updated Common_Consequences, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2012-10-30CWE Content TeamMITRE
updated Potential_Mitigations
2014-02-18CWE Content TeamMITRE
updated Relationships
2014-06-23CWE Content TeamMITRE
updated Observed_Examples
2014-07-30CWE Content TeamMITRE
updated Demonstrative_Examples, Relationships
2017-11-08CWE Content TeamMITRE
updated Applicable_Platforms, Modes_of_Introduction, Relationships
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Man-in-the-middle (MITM)
2009-05-27Channel Accessible by Non-Endpoint (aka 'Man-in-the-Middle')

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Page Last Updated: January 18, 2018