Authentication / Authentication Bypass Using an Alternate Path or Channel

Description

Authentication Bypass Using an Alternate Path or Channel (CWE-287) is a vulnerability that can occur when authentication is not properly enforced, or when an alternate path or channel is used to bypass authentication. In web and API applications, this can occur when an attacker can gain access to an application through an alternate path or channel, which is not adequately protected, and can therefore bypass authentication. This vulnerability is described in the Common Weakness Enumeration (CWE) directory and OWASP Testing Guide.

Risk

This vulnerability can have significant consequences, since an attacker can gain access to the application without having to authenticate. This can lead to unauthorized access to sensitive data, as well as manipulation of data or other malicious activity. The risk assessment should consider the type of data the application contains and the potential impact of unauthorized access.

Solution

In order to mitigate this vulnerability, authentication should be enforced on all paths and channels. The authentication mechanism should also be strong, using a combination of different authentication factors, such as passwords, tokens, and biometrics. Additionally, all authentication requests should be logged and monitored for suspicious activity.

Example

# Insecure web application

//authentication check
if (username == 'admin' && password == 'admin')
{
  //grant access
}

//alternate path
if (session_token == '12345')
{
  //grant access
}

In the example above, the application is vulnerable to Authentication Bypass Using an Alternate Path or Channel, since it does not properly enforce authentication when the session token is provided.