gix traversal outside working tree enables arbitrary code execution
Date: 2024-05
Affected: rust/gix-index, rust/gitoxide-core, rust/gix
Attack vector: rce
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2024-35186
CWE: CWE-22
CWE-23
CVSS: 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

### Summary During checkout, gitoxide does not verify that paths point to locations in the working tree. A specially crafted repository can, when cloned, place new files anywhere writable by the application. ### Details Although `gix-worktree-state` checks for collisions with existing files, it does not itself check if a path is really in the working tree when performing a checkout, nor do the path checks in `gix-fs` and `gix-worktree` prevent this. Cloning an untrusted repository containing specially crafted tree or blob names will create new files outside the repository, or inside the repository or a submodule's `.git` directory. The simplest cases are: - A tree named `..` to traverse upward. This facilitates arbitrary code execution because files can be placed in one or more locations where they are likely to be executed soon. - A tree named `.git` to enter a `.git` directory. This facilitates arbitrary code execution because hooks can be installed. A number of alternatives that achieve the same effect are also possible, some of which correspond to specific vulnerabilities that have affected Git in the past: - A tree or blob whose name contains one or more `/`, to traverse upward or downward. For example, even without containing any tree named `..` or `.git`, a repository can represent a file named `../outside` or `.git/hooks/pre-commit`. This is distinct from the more intuitive case a repository containing trees that represent those paths. - In Windows, a tree or bl


Mitigations:

Architectural layers (MAESTRO):