GHSA-3rp5-jjmw-4wv2

### Summary In GitPython `<= 3.1.52`, the config writer neutralizes only CR, LF, and NUL in configuration **names**, but writes section names into the `[...]` header with no other escaping. A section/subsection name that contains `] [ "` closes the intended header and opens a second same-line section, injecting an arbitrary config directive — with no newline required. Because a submodule **name** is attacker-controlled data (it comes from a repository's `.gitmodules`, or from an application that lets a user name a submodule) and is written verbatim into the parent repository's trusted `.git/config`, an attacker can set `core.sshCommand` (or `alias.*`, `core.pager`, `core.fsmonitor`) and achieve remote code execution on the victim's next git operation. Likely **CWE-74 (Injection)**. This is a distinct variant of the injection addressed by GHSA-mv93-w799-cj2w / GHSA-v87r-6q3f-2j67: those fixed **newline** injection into config values/names (patched in 3.1.50); the `[r\n\x00]` guard added for them does not stop a **same-line** section break inside a name. ### Details The only guard applied to section/option names before writing is `_assure_config_name_safe`, which uses a regex that matches solely CR/LF/NUL: `git/config.py:75,897-899` (`GitPython 3.1.52`): ```python UNSAFE_CONFIG_CHARS_RE = re.compile(r"[\r\n\x00]") ... def _assure_config_name_safe(self, name: "cp._SectionName", label: str) -> None: if isinstance(name, str) and UNSAFE_CONFIG_CHARS_RE.search(name): raise ValueError("Git config %s names must not contain CR, LF, or NUL" % label) ``` The name is then serialized into the header with no escaping of `]`, `[`, `"`, space, `=` or `#`: `git/config.py:693`: ```python fp.write(("[%s]\n" % name).encode(defenc)) ``` For submodules the name is wrapped as `submodule "<name>"` (`git/objects/submodule/util.py:39`, `return f'submodule "{name}"'`), which supplies the balancing quote. A submodule named: ``` x"] [core] sshCommand=CMD # ``` therefore s