🛡️ Sentinel: [security improvement] Remove shell wrapper for docker prune execution

.jules/sentinel.md

@@ -0,0 +1,4 @@
+## 2024-05-24 - Process execution via shell wrapper
+**Vulnerability:** Execution of command `docker system prune -f 2>&1` via `/bin/bash -c` in `CacheoutViewModel.swift`. Although there wasn't dynamic input here, using shell wrappers is a systemic risk for command injection in Swift.
+**Learning:** Shell redirections like `2>&1` can be replicated securely in Swift by assigning the same `Pipe()` instance to both `process.standardOutput` and `process.standardError` without needing `/bin/bash`.
+**Prevention:** Avoid shell wrappers (`/bin/bash -c`). Use direct executable invocation (e.g., `/usr/bin/env` with binary name) with an explicitly defined `arguments` array. Set stdout and stderr to the same `Pipe()` instance to capture combined output instead of relying on shell operators.

Sources/Cacheout/ViewModels/CacheoutViewModel.swift

@@ -231,8 +231,10 @@ class CacheoutViewModel: ObservableObject {
 
         let process = Process()
         let pipe = Pipe()
-        process.executableURL = URL(fileURLWithPath: "/bin/bash")
-        process.arguments = ["-c", "docker system prune -f 2>&1"]
+        // Run direct binary without shell wrapper to avoid command injection risks.
+        // The previous 2>&1 redirection is handled by assigning `pipe` to both stdout/stderr.
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+        process.arguments = ["docker", "system", "prune", "-f"]
         process.standardOutput = pipe
         process.standardError = pipe
         process.environment = [