Git for Windows versions prior to 2.55.0.windows.4 contain a vulnerability where a malicious remote Git server can cause the client to initiate outbound SMB connections during clone or fetch operations if transfer.bundleuri=true. This behavior can expose NTLM authentication credentials to an attacker-controlled host. The issue is resolved in version 2.55.0.windows.4.
Git for Windows is the Windows port of Git. Versions prior to 2.53.0.windows.3 do not have protections that prevent attackers from obtaining a user's NTLM hash. The NTLM hash can be obtained by tricking users into cloning a malicious repository, or checking out a malicious branch, that accesses an attacker-controlled server. By default, NTLM authentication does not need any user interaction. By brute-forcing the NTLMv2 hash (which is expensive, but possible), credentials can be extracted. This issue has been fixed in version 2.53.0.windows.3.
Git for Windows is the Windows port of Git. Prior to 2.53.0(2), it is possible to obtain a user's NTLM hash by tricking them into cloning from a malicious server. Since NTLM hashing is weak, it is possible for the attacker to brute-force the user's account name and password. This vulnerability is fixed in 2.53.0(2).
In Git for Windows, the Windows port of Git, no localized messages are shipped with the installer. As a consequence, Git is expected not to localize messages at all, and skips the gettext initialization. However, due to a change in MINGW-packages, the `gettext()` function's implicit initialization no longer uses the runtime prefix but uses the hard-coded path `C:\mingw64\share\locale` to look for localized messages. And since any authenticated user has the permission to create folders in `C:\` (and since `C:\mingw64` does not typically exist), it is possible for low-privilege users to place fake messages in that location where `git.exe` will pick them up in version 2.40.1.
This vulnerability is relatively hard to exploit and requires social engineering. For example, a legitimate message at the end of a clone could be maliciously modified to ask the user to direct their web browser to a malicious website, and the user might think that the message comes from Git and is legitimate. It does require local write access by the attacker, though, which makes this attack vector less likely. Version 2.40.1 contains a patch for this issue. Some workarounds are available. Do not work on a Windows machine with shared accounts, or alternatively create a `C:\mingw64` folder and leave it empty. Users who have administrative rights may remove the permission to create folders in `C:\`.