Git GUI is a convenient graphical tool that comes with Git for Windows. Its target audience is users who are uncomfortable with using Git on the command-line. Git GUI has a function to clone repositories. Immediately after the local clone is available, Git GUI will automatically post-process it, among other things running a spell checker called aspell.exe if it was found. Git GUI is implemented as a Tcl/Tk script. Due to the unfortunate design of Tcl on Windows, the search path when looking for an executable always includes the current directory. Therefore, malicious repositories can ship with an aspell.exe in their top-level directory which is executed by Git GUI without giving the user a chance to inspect it first, i.e. running untrusted code. This issue has been addressed in version 2.39.1. Users are advised to upgrade. Users unable to upgrade should avoid using Git GUI for cloning. If that is not a viable option, at least avoid cloning from untrusted sources.
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product’s direct control.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Git | Git-scm | * | 2.39.1 (excluding) |
| Git | Ubuntu | trusty | * |
| Git | Ubuntu | xenial | * |
This might allow attackers to execute their own programs, access unauthorized data files, or modify configuration in unexpected ways. If the product uses a search path to locate critical resources such as programs, then an attacker could modify that search path to point to a malicious program, which the targeted product would then execute. The problem extends to any type of critical resource that the product trusts. Some of the most common variants of untrusted search path are: