GitHub CLI (gh) is GitHubs official command line tool. Versions 2.28.0 through 2.97.0 bind the local listener created by gh codespace ports forward to all available network interfaces by default. While port forwarding is active, a service in a Codespace can therefore become reachable through the users non-loopback local IP addresses by other hosts that can route to the users machine. This behavior does not change the GitHub-side visibility of the Codespaces port. Instead, it exposes the forwarded service through a wildcard-bound listener on the users local machine, even when the source Codespaces port remains private. Exploitation requires a network-adjacent attacker to reach the victims machine while forwarding is active. This issue is fixed in version 2.98.0.
Weakness
The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.
Extended Description
Resources such as files and directories may be inadvertently exposed through mechanisms such as insecure permissions, or when a program accidentally operates on the wrong object. For example, a program may intend that private files can only be provided to a specific user. This effectively defines a control sphere that is intended to prevent attackers from accessing these private files. If the file permissions are insecure, then parties other than the user will be able to access those files. A separate control sphere might effectively require that the user can only access the private files, but not any other files on the system. If the program does not ensure that the user is only requesting private files, then the user might be able to access other files on the system. In either case, the end result is that a resource has been exposed to the wrong party.