CWE-300: Channel Accessible by Non-Endpoint ('Man-in-the-Middle')
Channel Accessible by Non-Endpoint ('Man-in-the-Middle')
Weakness ID: 300 (Weakness Class)
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.
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.
An attacker could pose as one of the entities and read or possibly
modify the communication.
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
sock = new Socket(REMOTE_HOST, REMOTE_PORT);
out = new PrintWriter(echoSocket.getOutputStream(),
// Write data to remote host via socket output
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')).
Always fully authenticate both ends of any communications
Phase: Architecture and Design
Adhere to the principle of complete mediation.
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.