PATH lookup
As per https://www.tcl.tk/man/tcl8.6/TclCmd/exec.html#M23, Tcl's `exec` function goes out of its way to imitate the highly dangerous path lookup of `cmd.exe`, but _of course_ only on Windows: If a directory name was not specified as part of the application name, the following directories are automatically searched in order when attempting to locate the application: The directory from which the Tcl executable was loaded. The current directory. The Windows 32-bit system directory. The Windows home directory. The directories listed in the path. The dangerous part is the second item, of course: `exec` _prefers_ executables in the current directory to those that are actually in the `PATH`. It is almost as if people wanted to Windows users vulnerable, specifically. To avoid that, Git GUI already has the `_which` function that does not imitate that dangerous practice when looking up executables in the search path. However, Git GUI currently fails to use that function e.g. when trying to execute `aspell` for spell checking. That is not only dangerous but combined with Tcl's unfortunate default behavior and with the fact that Git GUI tries to spell-check a repository just after cloning, leads to a critical Remote Code Execution vulnerability. Let's override both `exec` and `open` to always use `_which` instead of letting Tcl perform the path lookup, to prevent this attack vector. This addresses CVE-2022-41953. For more details, see https://github.com/git-for-windows/git/security/advisories/GHSA-v4px-mx59-w99c Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.
Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks