GitHub Desktop is an open-source, Electron-based GitHub app designed for git development. Prior to version 3.4.20-beta3, an attacker convincing a user to view a file in a commit of their making in the history view can cause information disclosure by means of Git attempting to access a network share. This affects GitHub Desktop users on Windows that view malicious commits in the history view. macOS users are not affected. When viewing a file diff in the history view GitHub Desktop will call git log or git diff with the object id (SHA) of the commit, the name of the file, and the old name of the file if the file has been renamed. As a security precaution Git will attempt to fully resolve the old and new path via realpath, traversing symlinks, to ensure that the resolved paths reside within the repository working directory. This can lead to Git attempting to access a path that resides on a network share (UNC path) and in doing so Windows will attempt to perform NTLM authentication which passes information such as the computer name, the currently signed in (Windows) user name, and an NTLM hash. GitHub Desktop 3.4.20 and later fix this vulnerability. The beta channel includes the fix in 3.4.20-beta3. As a workaround to use until upgrading is possible, only browse commits in the history view that comes from trusted sources.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:
Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:
Information exposures can occur in different ways:
It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.