GHSA-PG4W-G64P-QWHJ
Vulnerability from github – Published: 2026-05-05 19:26 – Updated: 2026-05-05 19:26Summary
attachments: pocs.zip
When Repository::submodules() loads submodule metadata, it prefers the worktree .gitmodules file if that path exists. In the current implementation, the path is read with std::fs::read(), which follows symlinks. As a result, a repository can present a symlinked .gitmodules that points outside the repository, and gitoxide will parse the out-of-repository bytes as submodule configuration.
This is a repository-boundary violation. A caller using the high-level submodule API can believe it is reading repository-local submodule metadata, while the bytes are actually coming from an arbitrary file outside the repository tree.
Root cause analysis
The relevant flow is:
gix/src/repository/location.rsderives the worktree.gitmodulespath asworkdir/.gitmodules.gix/src/repository/submodule.rsreads that path withstd::fs::read(&path)and immediately parses the bytes as a submodule configuration file.Repository::submodules()exposes the parsed entries through the high-level API.
The issue is not in the parser. The issue is that the worktree path is treated as an ordinary file without checking whether it is a symlink, and without checking whether the canonicalized target remains inside the repository worktree.
Because std::fs::read() follows symlinks, a malicious repository can cause gitoxide to ingest bytes from an attacker-chosen location outside the repository. The resulting Submodule objects then expose name, path, and url values derived from that external file.
Reproduction steps
Use the attached PoC zip that contains the pocs/ workspace.
- Unzip the PoC archive.
- Enter
pocs/F001. -
Run:
bash cargo run --quiet -
Compare the output with
pocs/F001/result.txt.
Important outputs include:
gitmodules_symlink=.../victim-repo/.gitmodulessymlink_target=.../outside/modules.confparsed_name=symlinkedparsed_path=deps/symlinkedparsed_url=https://attacker.example/symlinked.git
These outputs show that gitoxide parsed the submodule configuration from the symlink target outside the repository, not from repository-local bytes.
Impact
Confirmed impact:
- out-of-repository bytes can be injected into the result of
Repository::submodules(); - callers can be misled about submodule metadata such as
name,path, andurl; - any downstream workflow that uses those values to decide clone, fetch, update, or policy behavior is operating on attacker-controlled data that did not actually originate from the repository tree.
This report does not claim direct command execution from this code path by itself. The demonstrated impact is metadata injection across the repository boundary.
Recommended fix
A safe fix is to stop silently following symlinks for the worktree .gitmodules path in this loading path.
Reasonable options include:
- use
symlink_metadata()/lstatstyle checks and reject symlinked.gitmoduleswhen loading from the worktree; - canonicalize the target and verify that it still resides under the repository worktree before reading it;
- for security-sensitive callers, prefer loading
.gitmodulesfrom the index orHEADtree rather than following the worktree path.
At minimum, the worktree path should not silently follow symlinks to arbitrary external files.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.52.0"
},
"package": {
"ecosystem": "crates.io",
"name": "gitoxide"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.52.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "gix"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.83.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-05T19:26:09Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\nattachments:\n[pocs.zip](https://github.com/user-attachments/files/26431422/pocs.zip)\n\n\nWhen `Repository::submodules()` loads submodule metadata, it prefers the worktree `.gitmodules` file if that path exists. In the current implementation, the path is read with `std::fs::read()`, which follows symlinks. As a result, a repository can present a symlinked `.gitmodules` that points outside the repository, and gitoxide will parse the out-of-repository bytes as submodule configuration.\n\nThis is a repository-boundary violation. A caller using the high-level submodule API can believe it is reading repository-local submodule metadata, while the bytes are actually coming from an arbitrary file outside the repository tree.\n\n## Root cause analysis\n\nThe relevant flow is:\n\n1. [`gix/src/repository/location.rs`](https://github.com/GitoxideLabs/gitoxide/blob/v0.52.0/gix/src/repository/location.rs) derives the worktree `.gitmodules` path as `workdir/.gitmodules`.\n2. [`gix/src/repository/submodule.rs`](https://github.com/GitoxideLabs/gitoxide/blob/v0.52.0/gix/src/repository/submodule.rs) reads that path with `std::fs::read(\u0026path)` and immediately parses the bytes as a submodule configuration file.\n3. `Repository::submodules()` exposes the parsed entries through the high-level API.\n\nThe issue is not in the parser. The issue is that the worktree path is treated as an ordinary file without checking whether it is a symlink, and without checking whether the canonicalized target remains inside the repository worktree.\n\nBecause `std::fs::read()` follows symlinks, a malicious repository can cause gitoxide to ingest bytes from an attacker-chosen location outside the repository. The resulting `Submodule` objects then expose `name`, `path`, and `url` values derived from that external file.\n\n## Reproduction steps\n\nUse the attached PoC zip that contains the `pocs/` workspace.\n\n1. Unzip the PoC archive.\n2. Enter `pocs/F001`.\n3. Run:\n \n ```bash\n cargo run --quiet\n ```\n \n4. Compare the output with `pocs/F001/result.txt`.\n\nImportant outputs include:\n\n- `gitmodules_symlink=.../victim-repo/.gitmodules`\n- `symlink_target=.../outside/modules.conf`\n- `parsed_name=symlinked`\n- `parsed_path=deps/symlinked`\n- `parsed_url=https://attacker.example/symlinked.git`\n\nThese outputs show that gitoxide parsed the submodule configuration from the symlink target outside the repository, not from repository-local bytes.\n\n## Impact\n\nConfirmed impact:\n\n- out-of-repository bytes can be injected into the result of `Repository::submodules()`;\n- callers can be misled about submodule metadata such as `name`, `path`, and `url`;\n- any downstream workflow that uses those values to decide clone, fetch, update, or policy behavior is operating on attacker-controlled data that did not actually originate from the repository tree.\n\nThis report does **not** claim direct command execution from this code path by itself. The demonstrated impact is metadata injection across the repository boundary.\n\n## Recommended fix\n\nA safe fix is to stop silently following symlinks for the worktree `.gitmodules` path in this loading path.\n\nReasonable options include:\n\n1. use `symlink_metadata()` / `lstat`style checks and reject symlinked `.gitmodules` when loading from the worktree;\n2. canonicalize the target and verify that it still resides under the repository worktree before reading it;\n3. for security-sensitive callers, prefer loading `.gitmodules` from the index or `HEAD` tree rather than following the worktree path.\n\nAt minimum, the worktree path should not silently follow symlinks to arbitrary external files.",
"id": "GHSA-pg4w-g64p-qwhj",
"modified": "2026-05-05T19:26:09Z",
"published": "2026-05-05T19:26:09Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/GitoxideLabs/gitoxide/security/advisories/GHSA-pg4w-g64p-qwhj"
},
{
"type": "PACKAGE",
"url": "https://github.com/GitoxideLabs/gitoxide"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "gix and gitoxide\u0027s symlinked .gitmodules are followed and parsed from outside of the repository"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.