fix: prevent command injection and fix cross-platform compatibility

[VivanRajath]

fix: prevent command injection and fix cross-platform compatibility

Problem

Multiple files use execSync() with string interpolation to run git commands. User-controlled inputs (branch names, commit messages, URLs) are interpolated directly into shell strings, enabling arbitrary command execution:

// Before — vulnerable to injection via branch name
function git(args: string, cwd: string): string {
    return execSync(`git ${args}`, { cwd, stdio: "pipe", encoding: "utf-8" }).trim();
}
git(`checkout -b ${branch}`, dir);  // branch = "; rm -rf /" → executes arbitrary command

Additionally:

• Shell tools (cli, hooks, tool-loader) use sh which doesn't exist on Windows, breaking core command execution on that platform.
• The hook path traversal guard uses hardcoded / instead of path.sep, completely bypassing the security check on Windows (which uses \).

Solution

1. Command Injection → Safe Argument Arrays

Replaced every execSync with string interpolation with execFileSync using argument arrays. Inputs are passed as separate OS-level arguments and are never interpreted by a shell:

// After — safe, inputs cannot be interpreted as shell commands
function git(args: string[], cwd: string): string {
    return execFileSync("git", args, { cwd, stdio: "pipe", encoding: "utf-8" }).trim();
}
git(["checkout", "-b", branch], dir);  // branch is always treated as a literal string

For compound git operations (e.g., git add && git commit), the single shell command was split into separate execFileSync calls:

// Before — single shell command with string interpolation
execSync(`git add "${memoryPath}" && git commit -m "${commitMsg.replace(/"/g, '\\"')}"`, ...);

// After — separate safe calls, no quote escaping needed
execFileSync("git", ["add", memoryPath], { cwd, stdio: "pipe" });
execFileSync("git", ["commit", "-m", commitMsg], { cwd, stdio: "pipe" });

2. Cross-Platform Shell Execution

Shell-spawning tools now detect the platform and use the appropriate shell:

const isWin = process.platform === "win32";
const child = spawn(isWin ? "cmd" : "sh", isWin ? ["/c", command] : ["-c", command], ...);

3. Path Traversal Guard Fix

-if (!resolvedScript.startsWith(allowedBase + "/") && resolvedScript !== allowedBase) {
+if (!resolvedScript.startsWith(allowedBase + sep) && resolvedScript !== allowedBase) {

Files Changed (12)

File	Change
src/session.ts	git() helper rewritten + all 15 call sites
src/loader.ts	git clone in resolveInheritance() and resolveDependencies()
src/index.ts	isGitRepo(), ensureRepo() git init/add/commit
src/tools/memory.ts	Memory save git add + commit
src/sandbox.ts	git remote get-url origin
src/tools/skill-learner.ts	gitCommit() helper + delete action
src/tools/capture-photo.ts	Photo commit git add + commit
src/plugin-cli.ts	Removed unused execSync import
src/tools/cli.ts	Cross-platform shell (sh/cmd)
src/hooks.ts	Path traversal guard (path.sep) + cross-platform shell
src/tool-loader.ts	Declarative tool scripts cross-platform shell

Not Included

src/voice/server.ts still uses execSync — it's a 113KB monolith that needs a refactor before these changes can be applied safely. Planned for a follow-up PR.

Testing

-tsc --noEmit passes with zero compilation errors
-npm test passes with zero compilation errors

• No behavioral changes — all functions maintain identical semantics
• The only difference is that inputs can no longer escape their argument boundaries