Affected versions of Git have a vulnerability whereby Git can be tricked into sending private credentials to a host controlled by an attacker. Git uses external "credential helper" programs to store and retrieve passwords or other credentials from secure storage provided by the operating system. Specially-crafted URLs that contain an encoded newline can inject unintended values into the credential helper protocol stream, causing the credential helper to retrieve the password for one server (e.g., good.example.com) for an HTTP request being made to another server (e.g., evil.example.com), resulting in credentials for the former being sent to the latter. There are no restrictions on the relationship between the two, meaning that an attacker can craft a URL that will present stored credentials for any host to a host of their choosing. The vulnerability can be triggered by feeding a malicious URL to git clone. However, the affected URLs look rather suspicious; the likely vector would be through systems which automatically clone URLs not visible to the user, such as Git submodules, or package systems built around Git. The problem has been patched in the versions published on April 14th, 2020, going back to v2.17.x. Anyone wishing to backport the change further can do so by applying commit 9a6bbee (the full release includes extra checks for git fsck, but that commit is sufficient to protect clients against the vulnerability). The patched versions are: 2.17.4, 2.18.3, 2.19.4, 2.20.3, 2.21.2, 2.22.3, 2.23.2, 2.24.2, 2.25.3, 2.26.1.
Git before 1.8.5.6, 1.9.x before 1.9.5, 2.0.x before 2.0.5, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 on Windows and OS X; Mercurial before 3.2.3 on Windows and OS X; Apple Xcode before 6.2 beta 3; mine all versions before 08-12-2014; libgit2 all versions up to 0.21.2; Egit all versions before 08-12-2014; and JGit all versions before 08-12-2014 allow remote Git servers to execute arbitrary commands via a tree containing a crafted .git/config file with (1) an ignorable Unicode codepoint, (2) a git~1/config representation, or (3) mixed case that is improperly handled on a case-insensitive filesystem.
An issue was found in Git before v2.24.1, v2.23.1, v2.22.2, v2.21.1, v2.20.2, v2.19.3, v2.18.2, v2.17.3, v2.16.6, v2.15.4, and v2.14.6. The --export-marks option of git fast-import is exposed also via the in-stream command feature export-marks=... and it allows overwriting arbitrary paths.
An issue was found in Git before v2.24.1, v2.23.1, v2.22.2, v2.21.1, v2.20.2, v2.19.3, v2.18.2, v2.17.3, v2.16.6, v2.15.4, and v2.14.6. When running Git in the Windows Subsystem for Linux (also known as "WSL") while accessing a working directory on a regular Windows drive, none of the NTFS protections were active.
An issue was found in Git before v2.24.1, v2.23.1, v2.22.2, v2.21.1, v2.20.2, v2.19.3, v2.18.2, v2.17.3, v2.16.6, v2.15.4, and v2.14.6. Recursive clones are currently affected by a vulnerability that is caused by too-lax validation of submodule names, allowing very targeted attacks via remote code execution in recursive clones.
Arbitrary command execution is possible in Git before 2.20.2, 2.21.x before 2.21.1, 2.22.x before 2.22.2, 2.23.x before 2.23.1, and 2.24.x before 2.24.1 because a "git submodule update" operation can run commands found in the .gitmodules file of a malicious repository.
Git before 2.19.2 on Linux and UNIX executes commands from the current working directory (as if '.' were at the end of $PATH) in certain cases involving the run_command() API and run-command.c, because there was a dangerous change from execvp to execv during 2017.
Git before 2.14.5, 2.15.x before 2.15.3, 2.16.x before 2.16.5, 2.17.x before 2.17.2, 2.18.x before 2.18.1, and 2.19.x before 2.19.1 allows remote code execution during processing of a recursive "git clone" of a superproject if a .gitmodules file has a URL field beginning with a '-' character.
In Git before 2.13.7, 2.14.x before 2.14.4, 2.15.x before 2.15.2, 2.16.x before 2.16.4, and 2.17.x before 2.17.1, code to sanity-check pathnames on NTFS can result in reading out-of-bounds memory.
In Git before 2.13.7, 2.14.x before 2.14.4, 2.15.x before 2.15.2, 2.16.x before 2.16.4, and 2.17.x before 2.17.1, remote code execution can occur. With a crafted .gitmodules file, a malicious project can execute an arbitrary script on a machine that runs "git clone --recurse-submodules" because submodule "names" are obtained from this file, and then appended to $GIT_DIR/modules, leading to directory traversal with "../" in a name. Finally, post-checkout hooks from a submodule are executed, bypassing the intended design in which hooks are not obtained from a remote server.