Man in the Middle Attack
Attack Pattern ID: 94 (Standard Attack Pattern Completeness: Complete)Typical Severity: Very HighStatus: Draft
+ Description


This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakeage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Attack Execution Flow

  1. The attacker probes to determine the nature and mechanism of communication between two components looking for opportunities to exploit.

  2. The attacker inserts himself into the communication channel initially acting as a routing proxy between the two targeted components. The attacker may or may not have to use cryptography.

  3. The attacker observes, filters or alters passed data of its choosing to gain access to sensitive information or to manipulate the actions of the two target components for his own purposes.

+ Attack Prerequisites

There are two components communicating with each other.

An attacker is able to identify the nature and mechanism of communication between the two target components.

An attacker can eavesdrop on the communication between the target components.

Strong mutual authentication is not used between the two target components yielding opportunity for attacker interposition.

The communication occurs in clear (not encrypted) or with insufficient and spoofable encryption.

+ Typical Likelihood of Exploit

Likelihood: Very High

+ Methods of Attack
  • Spoofing
  • Analysis
  • Modification of Resources
+ Examples-Instances


Symantec Scan Engine, and possibly other versions before, uses the same private DSA key for each installation, which allows remote attackers to conduct man-in-the-middle attacks and decrypt communications.

Related Vulnerabilities


+ Attacker Skills or Knowledge Required

Skill or Knowledge Level: Medium

This attack can get sophisticated since the attack may use cryptography.

+ Probing Techniques

The attacker can try to get the public-keys of the victims.

There are free software tool to perform man in the middle attack (packet anlaysis, etc.)

+ Solutions and Mitigations

Get your Public Key signed by a Certificate Authority

Encrypt your communication using cryptography (SSL,...)

Use Strong mutual authentication to always fully authenticate both ends of any communications channel.

Exchange public keys using a secure channel

+ Attack Motivation-Consequences
  • Data Modification
  • Privilege Escalation
  • Information Leakage
+ Injection Vector

The captured or modified data in transit

+ Payload

The new value of the data or the replay of the same data (e.g. credential)

+ Activation Zone

The messages exchanged between the two target hosts.

+ Payload Activation Impact

Privilege escalation. modification of resource, information leakage, etc.

+ Related Weaknesses
CWE-IDWeakness NameWeakness Relationship Type
300Channel Accessible by Non-Endpoint ('Man-in-the-Middle')Targeted
290Authentication Bypass by SpoofingSecondary
593Authentication Bypass: OpenSSL CTX Object Modified after SSL Objects are CreatedSecondary
287Improper AuthenticationTargeted
294Authentication Bypass by Capture-replaySecondary
724OWASP Top Ten 2004 Category A3 - Broken Authentication and Session ManagementSecondary
+ Related Attack Patterns
NatureTypeIDNameDescriptionView(s) this relationship pertains toView\(s\)
ChildOfAttack PatternAttack Pattern22Exploiting Trust in Client (aka Make the Client Invisible) 
Mechanism of Attack (primary)1000
ChildOfAttack PatternAttack Pattern151Identity Spoofing (Impersonation) 
Mechanism of Attack (primary)1000
ParentOfAttack PatternAttack Pattern57Utilizing REST's Trust in the System Resource to Register Man in the Middle 
Mechanism of Attack (primary)1000
ParentOfAttack PatternAttack Pattern219XML Routing Detour Attacks 
Mechanism of Attack (primary)1000
+ Related Security Principles
  • Complete Mediation

+ Purposes
  • Exploitation
+ CIA Impact
Confidentiality Impact: HighIntegrity Impact: HighAvailability Impact: High
+ Technical Context
Architectural Paradigms
+ References

CWE - Man-in-the-middle (MITM)

M. Bishop. Computer Security: Art and Science. Addison-Wesley, 2003.

+ Content History
Sean BarnumCigital, Inc.2007-03-25Identified priority for pattern creation
Eric DalciCigital, Inc.2007-03-25Fleshed out content for pattern
Sean BarnumCigital, Inc2007-04-16Review and revise