CWE-300: Channel Accessible by Non-Endpoint

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.

Affected languages: Not Language-Specific
Parent weaknesses: CWE-923

Consequences:
  - Confidentiality: Read Application Data

Detection methods:
  - Automated Dynamic Analysis: Some tools can act as proxy servers that allow the tester to intercept packets or messages, inspect them, and modify them before sending them to the destination in order to see if the modified packets
  - Automated Dynamic Analysis: Dynamic Application Security Testing (DAST) tools can be used to detect network traffic without encryption and/or verification. The affected protocol may be subject to Adversary-in-the-Middle attacks.
  - 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 havin

Mitigations:
  - [Implementation] Always fully authenticate both ends of any communications channel.
  - [Architecture and Design] Adhere to the principle of complete mediation.
  - [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 certificat

Demonstrative examples:
In the Java snippet below, data is sent over an unencrypted channel to a remote server.
By eavesdropping on the communication channel or posing as the endpoint, an attacker would be able to read all of the transmitted data.
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. 
                            ... 
                      }

Real-world examples:
  - CVE-2014-1266: Chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing Adversary-in-the-Middle (AITM) attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-56