fix: reject remote-helper git flags that enable RCE

[EndBug]

Summary

• Reject --upload-pack, --receive-pack, --exec, and Git-style abbreviations in matchGitArgs so expression-injected fetch/pull/push/tag_push inputs cannot trigger local command execution via remote-helper overrides.
• Add Jest coverage for safe args and PoC/bypass cases, document the restriction in the README, and rebuild lib/.

Test plan

• npm test passes (matchGitArgs allow/reject cases + lint)
• Confirm a workflow using default fetch: --tags --force still works
• Confirm args like --upload-pack=... / --receive-pack=... / --exec=... fail the action before git runs

Made with Cursor

Summary by CodeRabbit

• Security

  • Blocked dangerous Git remote-helper overrides that could execute local programs.
  • Added protection against full option names and recognized abbreviations.

• Documentation

  • Added guidance for sanitizing untrusted data used in Git operations.

• Maintenance

  • Updated Git integration support for improved compatibility and security.

• Tests

  • Expanded coverage for safe argument parsing, empty input, blocked overrides, and abbreviated options.

[coderabbitai]

Important

Review skipped

Review was skipped as selected files did not have any reviewable changes.

💤 Files selected but had no reviewable changes (1)

• lib/index.js

⛔ Files ignored due to path filters (1)

• package-lock.json is excluded by !**/package-lock.json

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 22df3c90-8816-4243-84e4-4d2da18b3ce0

📥 Commits

Reviewing files that changed from the base of the PR and between c4b60f7 and c437b74.

⛔ Files ignored due to path filters (1)

• package-lock.json is excluded by !**/package-lock.json

📒 Files selected for processing (1)

• lib/index.js

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📝 Walkthrough

Walkthrough

The change adds Git remote-helper option filtering, rejects executable override arguments in matchGitArgs, documents security rules, upgrades simple-git, and tests safe and blocked argument forms.

Changes

Git argument security

Layer / File(s)	Summary
Remote-helper override validation src/util.ts, README.md, package.json	matchGitArgs rejects upload-pack, receive-pack, and exec options, including abbreviations and value-bearing forms. The documentation describes the rejection and input sanitization rules. simple-git is upgraded to ^3.36.0.
Argument validation coverage test/util.test.ts	Tests cover safe arguments, blank input, blocked options, abbreviations, and value-bearing variants.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main security fix: rejecting Git remote-helper flags that could enable remote code execution.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch cursor/3c9e73ae

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/util.ts`:
- Around line 43-50: The dangerous-option filtering around
DANGEROUS_REMOTE_HELPER_OPTIONS must reject every valid nonempty prefix of each
canonical option, including short unambiguous forms such as upload-pack’s “upl”.
Replace the current minPrefix-based thresholds with logic or data representing
the true shortest valid prefixes, and update test/util.test.ts lines 86-92 to
cover these short-prefix cases.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 0d6f6a04-f605-4fb5-96f4-b8a3be1f8716

📥 Commits

Reviewing files that changed from the base of the PR and between 2b9ea5b and 5ebe3d7.

⛔ Files ignored due to path filters (1)

• package-lock.json is excluded by !**/package-lock.json

📒 Files selected for processing (5)

• README.md
• lib/index.js
• package.json
• src/util.ts
• test/util.test.ts