fix(editor): harden Windows subprocess argument quoting and prevent command injection on Windows by zainnadeem786 · Pull Request #29510 · google-gemini/gemini-cli

zainnadeem786 · 2026-09-26T06:51:36Z

Summary

This PR hardens Windows subprocess execution in packages/core/src/utils/editor.ts by introducing a robust argument quoting helper (quoteCmdArg) for shell: true invocations.

Problem / Vulnerability Addressed

When spawning diff commands on Windows using shell: true, file paths and arguments containing spaces, quotes, or shell metacharacters (&, |, ^, %VAR%) were passed unquoted to cmd.exe. This created risks of:

Argument Splitting: Paths with spaces (e.g., C:\Program Files\...) were split into multiple arguments.
Command Injection / Metacharacter Evaluation: Special characters in filenames could be interpreted as command separators or redirection operators by cmd.exe.
Environment Variable Expansion: %VAR% sequences inside paths could trigger unintended variable expansion.

Solution & Key Changes

quoteCmdArg Implementation:
- Safely preserves alphanumeric characters, hyphens, underscores, dots, colons, and forward/backward slashes.
- Automatically wraps arguments with spaces or special characters in double quotes.
- Escapes internal double quotes (" -> "") and carets (% -> ^%) to neutralize cmd.exe variable expansion.
- Properly handles trailing backslashes so cmd.exe / CommandLineToArgvW does not misinterpret quotes.
Platform-Specific Quoting: Refactored openDiff to map quoteCmdArg across diffCommand.args exclusively when process.platform === 'win32'.
Automated Testing: Added extensive unit test suites in packages/core/src/utils/editor.test.ts covering safe paths, edge cases, special characters, and cross-platform consistency.

Test Verification

Core editor unit tests (editor.test.ts): 233 / 233 passed (100%)
Linter & Typecheck: Clean (0 errors, 0 warnings)

Relates to #29625

…mmand injection

gemini-code-assist · 2026-09-26T06:51:43Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a security vulnerability in Windows subprocess execution where file paths and arguments were passed unquoted to cmd.exe. By implementing a specialized quoting mechanism, the changes prevent malicious command injection and ensure that paths containing spaces or shell metacharacters are handled correctly by the Windows shell.

Highlights

Security Hardening: Introduced a robust quoteCmdArg utility to safely escape and quote arguments when spawning subprocesses on Windows, mitigating risks of command injection and argument splitting.
Platform-Specific Logic: Updated openDiff to conditionally apply argument quoting only when running on Windows, ensuring cross-platform compatibility.
Automated Testing: Added comprehensive unit tests covering various edge cases, including special shell characters, environment variable patterns, and path formatting.

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github-actions · 2026-09-26T06:51:48Z

📊 PR Size: size/M

Lines changed: 144
Additions: +142
Deletions: -2
Files changed: 2

gemini-code-assist

Code Review

This pull request introduces a quoteCmdArg utility in packages/core/src/utils/editor.ts to escape and quote command-line arguments when launching diff tools via cmd.exe on Windows, along with corresponding unit tests. However, the feedback highlights critical security and correctness vulnerabilities in the implementation of quoteCmdArg, including potential command injection via newlines, incorrect handling of percent signs, and nested double quotes. The reviewer has provided suggestions to address these issues and update the test assertions accordingly.

…dArg to prevent command injection

zainnadeem786 · 2026-09-26T07:06:47Z

@gemini-code-assist review

gemini-code-assist

Code Review

This pull request introduces a new utility function quoteCmdArg to safely quote arguments when spawning editor processes on Windows, preventing command injection and argument splitting. The reviewer identified an issue where escaping percent signs (%) with carets (^%) inside double quotes is incorrect because cmd.exe treats carets literally inside double quotes, which would corrupt paths containing %. The reviewer suggested removing this escaping and updating the corresponding test cases.

…ent path corruption on Windows

gemini-cli · 2026-10-04T02:22:22Z

Hi there! Thank you for your interest in contributing to Gemini CLI.

To ensure we maintain high code quality and focus on our prioritized roadmap, we only guarantee review and consideration of pull requests for issues that are explicitly labeled as 'help wanted'.

This PR will be closed in 7 days if it remains without that designation. We encourage you to find and contribute to existing 'help wanted' issues in our backlog! Thank you for your understanding.

fix(editor): harden Windows subprocess argument quoting to prevent co…

0d8667e

…mmand injection

zainnadeem786 requested a review from a team as a code owner September 26, 2026 06:51

github-actions Bot added the size/m A medium sized PR label Sep 26, 2026

gemini-code-assist Bot reviewed Sep 26, 2026

View reviewed changes

Comment thread packages/core/src/utils/editor.ts

Comment thread packages/core/src/utils/editor.test.ts Outdated

fix(editor): reject newline and carriage return characters in quoteCm…

e6b4bd5

…dArg to prevent command injection

gemini-code-assist Bot reviewed Sep 26, 2026

View reviewed changes

Comment thread packages/core/src/utils/editor.ts Outdated

Comment thread packages/core/src/utils/editor.test.ts Outdated

fix(editor): remove incorrect percent escaping in quoteCmdArg to prev…

3fd27a1

…ent path corruption on Windows

gemini-cli Bot added the status/need-issue Pull requests that need to have an associated issue. label Sep 26, 2026

This was referenced Sep 26, 2026

📊 AI CLI 工具社区动态日报 2026-09-27 litang9/big_model_radar#458

Open

📊 AI CLI 工具社区动态日报 2026-09-27 96loveslife/big_model_radar#553

Open

gemini-cli Bot added the status/pr-nudge-sent label Oct 4, 2026

github-actions Bot mentioned this pull request Oct 4, 2026

📊 AI CLI 工具社区动态日报 2026-10-04 96loveslife/big_model_radar#585

Open

zainnadeem786 mentioned this pull request Oct 4, 2026

[Bug] Windows path quoting and argument sanitization for editor diff command #29625

Open

gemini-cli Bot added priority/p2 Important but can be addressed in a future release. area/core Issues related to User Interface, OS Support, Core Functionality and removed status/need-issue Pull requests that need to have an associated issue. labels Oct 4, 2026

github-actions Bot mentioned this pull request Oct 4, 2026

📊 AI CLI 工具社区动态日报 2026-10-05 litang9/big_model_radar#498

Open

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fix(editor): harden Windows subprocess argument quoting and prevent command injection on Windows - #29510

fix(editor): harden Windows subprocess argument quoting and prevent command injection on Windows#29510
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zainnadeem786 commented Sep 26, 2026 •

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