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# Mole Security Audit Report # Mole Security Reference
<div align="center"> Version 1.23.2 | 2026-01-26
**Status:** PASSED | **Risk Level:** LOW | **Version:** 1.23.2 (2026-01-26) ## Recent Fixes
</div> **Uninstall audit, Jan 2026:**
--- - `stop_launch_services()` now checks bundle_id is valid reverse-DNS before using it in find patterns. This stops glob injection.
- `find_app_files()` skips LaunchAgents named after common words like Music or Notes.
- Added comments explaining why `remove_file_list()` bypasses TOCTOU checks for symlinks.
- `brew_uninstall_cask()` treats exit code 124 as timeout failure, returns immediately.
## Audit Overview Other changes:
| Attribute | Details | - Symlink cleanup in `bin/clean.sh` goes through `safe_remove` now
|-----------|---------| - Orphaned helper cleanup in `lib/clean/apps.sh` switched to `safe_sudo_remove`
| Audit Date | January 26, 2026 | - ByHost pref cleanup checks bundle ID format first
| Audit Conclusion | **PASSED** |
| Mole Version | V1.23.2 |
| Audited Branch | `main` (HEAD) |
| Scope | Shell scripts, Go binaries, Configuration |
| Methodology | Static analysis, Threat modeling, Code review |
| Review Cycle | Every 6 months or after major feature additions |
| Next Review | July 2026 |
**Key Findings:** ## Path Validation
- Multi-layer validation effectively blocks risky system modifications. Every deletion goes through `lib/core/file_ops.sh`. The `validate_path_for_deletion()` function rejects empty paths, paths with `/../` in them, and anything containing control characters like newlines or null bytes.
- Conservative cleaning logic ensures safety (e.g., 60-day dormancy rule).
- Comprehensive protection for VPNs, AI tools, and core system components.
- Operations logging improves traceability while remaining optional (MO_NO_OPLOG=1).
- Atomic operations prevent state corruption during crashes.
- Dry-run and whitelist features give users full control.
- Installer cleanup scans safely and requires user confirmation.
**Recent Remediations:** **Blocked paths**, even with sudo:
- **Uninstall Audit (Jan 2026)**: Enhanced security in uninstall logic per comprehensive security review. ```text
- `stop_launch_services()` now validates bundle_id format (reverse-DNS) before use in find patterns to prevent glob injection attacks. / # root
- `find_app_files()` LaunchAgents search now excludes common words (Music, Notes, etc.) to prevent false positive matches. /System # macOS system
- `remove_file_list()` symlink handling documented with detailed security comments explaining the TOCTOU protection bypass rationale. /bin, /sbin, /usr # binaries
- `brew_uninstall_cask()` timeout handling improved: exit code 124 (timeout) now returns failure immediately without verification. /etc, /var # config
- Symlink cleanup in `bin/clean.sh` now routes through `safe_remove` for target validation. /Library/Extensions # kexts
- Orphaned helper cleanup in `lib/clean/apps.sh` now uses `safe_sudo_remove`. /private # system private
- ByHost preference cleanup in `lib/uninstall/batch.sh` validates bundle IDs and deletes via `safe_remove`.
---
## Security Philosophy
**Core Principle: "Do No Harm"**
We built Mole on a **Zero Trust** architecture for filesystem operations. Every modification request is treated as dangerous until it passes strict validation.
**Guiding Priorities:**
1. **System Stability First** - We'd rather leave 1GB of junk than delete 1KB of your data.
2. **Conservative by Default** - High-risk operations always require explicit confirmation.
3. **Fail Safe** - When in doubt, we abort immediately.
4. **Transparency** - Every operation is logged and allows a preview via dry-run mode.
---
## Threat Model
### Attack Vectors & Mitigations
| Threat | Risk Level | Mitigation | Status |
|--------|------------|------------|--------|
| Accidental System File Deletion | Critical | Multi-layer path validation, system directory blocklist | Mitigated |
| Path Traversal Attack | High | Absolute path enforcement, relative path rejection | Mitigated |
| Symlink Exploitation | High | Symlink detection in privileged mode | Mitigated |
| Command Injection | High | Control character filtering, strict validation | Mitigated |
| Empty Variable Deletion | High | Empty path validation, defensive checks | Mitigated |
| Race Conditions | Medium | Atomic operations, process isolation | Mitigated |
| Network Mount Hangs | Medium | Timeout protection, volume type detection | Mitigated |
| Privilege Escalation | Medium | Restricted sudo scope, user home validation | Mitigated |
| False Positive Deletion | Medium | 3-char minimum, fuzzy matching disabled | Mitigated |
| VPN Configuration Loss | Medium | Comprehensive VPN/proxy whitelist | Mitigated |
---
## Defense Architecture
### Multi-Layered Validation System
All automated operations pass through hardened middleware (`lib/core/file_ops.sh`) with 4 layers of validation:
#### Layer 1: Input Sanitization
| Control | Protection Against |
|---------|---------------------|
| Absolute Path Enforcement | Path traversal attacks (`../etc`) |
| Control Character Filtering | Command injection (`\n`, `\r`, `\0`) |
| Empty Variable Protection | Accidental `rm -rf /` |
| Secure Temp Workspaces | Data leakage, race conditions |
**Code:** `lib/core/file_ops.sh:validate_path_for_deletion()`
#### Layer 2: System Path Protection ("Iron Dome")
Even with `sudo`, these paths are **unconditionally blocked**:
```bash
/ # Root filesystem
/System # macOS system files
/bin, /sbin, /usr # Core binaries
/etc, /var # System configuration
/Library/Extensions # Kernel extensions
/private # System-private directories
``` ```
**Exceptions:** Some system caches are OK to delete:
- `/System/Library/Caches/com.apple.coresymbolicationd/data` (safe, rebuildable cache) - `/System/Library/Caches/com.apple.coresymbolicationd/data`
- `/private/tmp`, `/private/var/tmp`, `/private/var/log`, `/private/var/folders` - `/private/tmp`, `/private/var/tmp`, `/private/var/log`, `/private/var/folders`
- `/private/var/db/diagnostics`, `/private/var/db/DiagnosticPipeline`, `/private/var/db/powerlog`, `/private/var/db/reportmemoryexception` - `/private/var/db/diagnostics`, `/private/var/db/DiagnosticPipeline`, `/private/var/db/powerlog`, `/private/var/db/reportmemoryexception`
**Code:** `lib/core/file_ops.sh:60-78` See `lib/core/file_ops.sh:60-78`.
#### Layer 3: Symlink Detection When running with sudo, `safe_sudo_recursive_delete()` also checks for symlinks. Refuses to follow symlinks pointing to system files.
For privileged operations, pre-flight checks prevent symlink-based attacks: ## Cleanup Rules
- Detects symlinks from cache folders pointing to system files. **Orphan detection** at `lib/clean/apps.sh:orphan_detection()`:
- Refuses recursive deletion of symbolic links in sudo mode.
- Validates real path vs. symlink target.
**Code:** `lib/core/file_ops.sh:safe_sudo_recursive_delete()` App data is only considered orphaned if the app itself is gone from all three locations: `/Applications`, `~/Applications`, `/System/Applications`. On top of that, the data must be untouched for at least 60 days. Adobe, Microsoft, and Google stuff is whitelisted regardless.
#### Layer 4: Permission Management **Uninstall matching** at `lib/clean/apps.sh:uninstall_app()`:
When running with `sudo`: App names need at least 3 characters. Otherwise "Go" would match "Google" and that's bad. Fuzzy matching is off. Receipt scans only look under `/Applications` and `/Library/Application Support`, not in shared places like `/Library/Frameworks`.
- Auto-corrects ownership back to user (`chown -R`). **Dev tools:**
- Restricts operations to the user's home directory.
- Enforces multiple validation checkpoints.
### Interactive Analyzer (Go) Cache dirs like `~/.cargo/registry/cache` or `~/.gradle/caches` get cleaned. But `~/.cargo/bin`, `~/.mix/archives`, `~/.rustup` toolchains, `~/.stack/programs` stay untouched.
The analyzer (`mo analyze`) uses a distinct security model: **LaunchAgent removal:**
- Runs with standard user permissions only. Only removed when uninstalling the app that owns them. All `com.apple.*` items are skipped. Services get stopped via `launchctl` first. Generic names like Music, Notes, Photos are excluded from the search.
- Respects macOS System Integrity Protection (SIP).
- **Two-Key Confirmation:** Deletion requires ⌫ (Delete) to enter confirmation mode, then Enter to confirm. Prevents accidental double-press of the same key.
- **Trash Instead of Delete:** Files are moved to macOS Trash using Finder's native API, allowing easy recovery if needed.
- OS-level enforcement (cannot delete `/System` due to Read-Only Volume).
**Code:** `cmd/analyze/*.go` See `lib/core/app_protection.sh:find_app_files()`.
--- ## Protected Categories
## Safety Mechanisms | Category | What's protected |
| -------- | ---------------- |
| System | Control Center, System Settings, TCC, `/Library/Updates`, Spotlight |
| VPN/Proxy | Shadowsocks, V2Ray, Tailscale, Clash |
| AI | Cursor, Claude, ChatGPT, Ollama, LM Studio |
| Time Machine | Checks if backup is running. If status unclear, skips cleanup. |
| Startup | `com.apple.*` LaunchAgents/Daemons always skipped |
### Conservative Cleaning Logic See `lib/core/app_protection.sh:is_critical_system_component()`.
#### The "60-Day Rule" for Orphaned Data ## Analyzer
| Step | Verification | Criterion | `mo analyze` runs differently:
|------|--------------|-----------|
| 1. App Check | All installation locations | Must be missing from `/Applications`, `~/Applications`, `/System/Applications` |
| 2. Dormancy | Modification timestamps | Untouched for ≥60 days |
| 3. Vendor Whitelist | Cross-reference database | Adobe, Microsoft, and Google resources are protected |
**Code:** `lib/clean/apps.sh:orphan_detection()` - Standard user permissions, no sudo
- Respects SIP
- Two keys to delete: press ⌫ first, then Enter. Hard to delete by accident.
- Files go to Trash via Finder API, not rm
#### Developer Tool Ecosystems (Consolidated) Code at `cmd/analyze/*.go`.
Support for 20+ languages (Rust, Go, Node, Python, JVM, Mobile, Elixir, Haskell, OCaml, etc.) with strict safety checks: ## Timeouts
- **Global Optimization:** The core `safe_clean` function now intelligently checks parent directories before attempting wildcard cleanups, eliminating overhead for missing tools across the entire system. | Operation | Timeout | Why |
- **Safe Targets:** Only volatile caches are cleaned (e.g., `~/.cargo/registry/cache`, `~/.gradle/caches`). | --------- | ------- | --- |
- **Protected Paths:** Critical directories like `~/.cargo/bin`, `~/.mix/archives`, `~/.rustup` toolchains, and `~/.stack/programs` are explicitly **excluded**. | Network volume check | 5s | NFS/SMB/AFP can hang forever |
| App bundle search | 10s | mdfind sometimes stalls |
| SQLite vacuum | 20s | Skip if Mail/Safari/Messages is open |
| dyld cache rebuild | 180s | Skip if done in last 24h |
#### Active Uninstallation Heuristics See `lib/core/base.sh:run_with_timeout()`.
For user-selected app removal: ## User Config
- **Sanitized Name Matching:** "Visual Studio Code" → `VisualStudioCode`, `.vscode` Put paths in `~/.config/mole/whitelist`, one per line:
- **Safety Limit:** 3-char minimum (prevents "Go" matching "Google")
- **Disabled:** Fuzzy matching and wildcard expansion for short names.
- **User Confirmation:** Required before deletion.
- **Receipt Scans:** BOM-derived files are restricted to app-specific prefixes (e.g., `/Applications`, `/Library/Application Support`). Shared directories like `/Library/Frameworks` are **excluded** to prevent collateral damage.
**Code:** `lib/clean/apps.sh:uninstall_app()`
#### System Protection Policies
| Protected Category | Scope | Reason |
|--------------------|-------|--------|
| System Integrity Protection | `/Library/Updates`, `/System/*` | Respects macOS Read-Only Volume |
| Spotlight & System UI | `~/Library/Metadata/CoreSpotlight` | Prevents UI corruption |
| System Components | Control Center, System Settings, TCC | Centralized detection via `is_critical_system_component()` |
| Time Machine | Local snapshots, backups | Runtime activity detection (backup running, snapshots mounted), fails safe if status indeterminate |
| VPN & Proxy | Shadowsocks, V2Ray, Tailscale, Clash | Protects network configs |
| AI & LLM Tools | Cursor, Claude, ChatGPT, Ollama, LM Studio | Protects models, tokens, and sessions |
| Startup Items | `com.apple.*` LaunchAgents/Daemons | System items unconditionally skipped |
**LaunchAgent/LaunchDaemon Cleanup During Uninstallation:**
When users uninstall applications via `mo uninstall`, Mole automatically removes associated LaunchAgent and LaunchDaemon plists:
- Scans `~/Library/LaunchAgents`, `~/Library/LaunchDaemons`, `/Library/LaunchAgents`, `/Library/LaunchDaemons`
- Matches both exact bundle ID (`com.example.app.plist`) and app name patterns (`*AppName*.plist`)
- Skips all `com.apple.*` system items via `should_protect_path()` validation
- Unloads services via `launchctl` before deletion (via `stop_launch_services()`)
- **Safer than orphan detection:** Only removes plists when the associated app is explicitly being uninstalled
- Prevents accumulation of orphaned startup items that persist after app removal
- **Common word exclusion:** LaunchAgent name searches exclude generic terms (Music, Notes, Photos, etc.) to prevent false positives
- **Bundle ID validation:** `stop_launch_services()` validates reverse-DNS format before find patterns
**Code:** `lib/core/app_protection.sh:find_app_files()`, `lib/uninstall/batch.sh:stop_launch_services()`
### Crash Safety & Atomic Operations
| Operation | Safety Mechanism | Recovery Behavior |
|-----------|------------------|-------------------|
| Network Interface Reset | Atomic execution blocks | Wi-Fi/AirDrop restored to pre-operation state |
| Swap Clearing | Daemon restart | `dynamic_pager` handles recovery safely |
| Volume Scanning | Timeout + filesystem check | Auto-skip unresponsive NFS/SMB/AFP mounts |
| Homebrew Cache | Pre-flight size check | Skip if <50MB (avoids long delays) |
| Network Volume Check | `diskutil info` with timeout | Prevents hangs on slow/dead mounts |
| SQLite Vacuum | App-running check + 20s timeout | Skips if Mail/Safari/Messages active |
| dyld Cache Update | 24-hour freshness check + 180s timeout | Skips if recently updated |
| App Bundle Search | 10s timeout on mdfind | Fallback to standard paths |
**Timeout Example:**
```bash ```bash
run_with_timeout 5 diskutil info "$mount_point" || skip_volume # exact matches only
/Users/me/important-cache
~/Library/Application Support/MyApp
``` ```
**Code:** `lib/core/base.sh:run_with_timeout()`, `lib/optimize/*.sh` These paths are protected from all operations.
--- Run `mo clean --dry-run` or `mo optimize --dry-run` to preview what would happen without actually doing it.
## User Controls ## Testing
### Dry-Run Mode | Area | Coverage |
| ---- | -------- |
| File ops | 95% |
| Cleaning | 87% |
| Optimize | 82% |
| System | 90% |
| Security | 100% |
**Command:** `mo clean --dry-run` | `mo optimize --dry-run` 180+ test cases total, about 88% coverage.
**Behavior:**
- Simulates the entire operation without modifying a single file.
- Lists every file/directory that **would** be deleted.
- Calculates total space that **would** be freed.
- **Zero risk** - no actual deletion commands are executed.
### Custom Whitelists
**File:** `~/.config/mole/whitelist`
**Format:**
```bash ```bash
# One path per line - exact matches only bats tests/ # run all
/Users/username/important-cache bats tests/security.bats # security only
~/Library/Application Support/CriticalApp
``` ```
- Paths are **unconditionally protected**. CI runs shellcheck and go vet on every push.
- Applies to all operations (clean, optimize, uninstall).
- Supports absolute paths and `~` expansion.
**Code:** `lib/core/file_ops.sh:is_whitelisted()`
### Interactive Confirmations
We mandate confirmation for:
- Uninstalling system-scope applications.
- Removing large data directories (>1GB).
- Deleting items from shared vendor folders.
---
## Testing & Compliance
### Test Coverage
Mole uses **BATS (Bash Automated Testing System)** for automated testing.
| Test Category | Coverage | Key Tests |
|---------------|----------|-----------|
| Core File Operations | 95% | Path validation, symlink detection, permissions |
| Cleaning Logic | 87% | Orphan detection, 60-day rule, vendor whitelist |
| Optimization | 82% | Cache cleanup, timeouts |
| System Maintenance | 90% | Time Machine, network volumes, crash recovery |
| Security Controls | 100% | Path traversal, command injection, symlinks |
**Total:** 180+ tests | **Overall Coverage:** ~88%
**Test Execution:**
```bash
bats tests/ # Run all tests
bats tests/security.bats # Run specific suite
```
### Standards Compliance
| Standard | Implementation |
|----------|----------------|
| OWASP Secure Coding | Input validation, least privilege, defense-in-depth |
| CWE-22 (Path Traversal) | Enhanced detection: rejects `/../` components, safely handles `..` in directory names |
| CWE-78 (Command Injection) | Control character filtering |
| CWE-59 (Link Following) | Symlink detection before privileged operations |
| Apple File System Guidelines | Respects SIP, Read-Only Volumes, TCC |
### Security Development Lifecycle
- **Static Analysis:** `shellcheck` runs on all shell scripts.
- **Code Review:** All changes are manually reviewed by maintainers.
- **Dependency Scanning:** Minimal external dependencies, all carefully vetted.
### Known Limitations
| Limitation | Impact | Mitigation |
|------------|--------|------------|
| Requires `sudo` for system caches | Initial friction | Clear documentation explaining why |
| 60-day rule may delay cleanup | Some orphans remain longer | Manual `mo uninstall` is always available |
| No undo functionality | Deleted files are unrecoverable | Dry-run mode and warnings are clear |
| English-only name matching | May miss non-English apps | Fallback to Bundle ID matching |
**Intentionally Out of Scope (Safety):**
- Automatic deletion of user documents/media.
- Encryption key stores or password managers.
- System configuration files (`/etc/*`).
- Browser history or cookies.
- Git repository cleanup.
---
## Dependencies ## Dependencies
### System Binaries System binaries used, all SIP protected:
Mole relies on standard, SIP-protected macOS system binaries: | Binary | For |
| ------ | --- |
| `plutil` | plist validation |
| `tmutil` | Time Machine |
| `dscacheutil` | cache rebuild |
| `diskutil` | volume info |
| Binary | Purpose | Fallback | Go libs in analyze-go:
|--------|---------|----------|
| `plutil` | Validate `.plist` integrity | Skip invalid plists |
| `tmutil` | Time Machine interaction | Skip TM cleanup |
| `dscacheutil` | System cache rebuilding | Optional optimization |
| `diskutil` | Volume information | Skip network volumes |
### Go Dependencies (Interactive Tools) | Lib | Version | License |
| --- | ------- | ------- |
| `bubbletea` | v0.23+ | MIT |
| `lipgloss` | v0.6+ | MIT |
| `gopsutil` | v3.22+ | BSD-3 |
| `xxhash` | v2.2+ | BSD-2 |
The compiled Go binary (`analyze-go`) includes: Versions are pinned. No CVEs. Binaries built via GitHub Actions.
| Library | Version | Purpose | License | ## Limitations
|---------|---------|---------|---------|
| `bubbletea` | v0.23+ | TUI framework | MIT |
| `lipgloss` | v0.6+ | Terminal styling | MIT |
| `gopsutil` | v3.22+ | System metrics | BSD-3 |
| `xxhash` | v2.2+ | Fast hashing | BSD-2 |
**Supply Chain Security:** | What | Impact | Workaround |
| ---- | ------ | ---------- |
| Needs sudo for system caches | Annoying first time | Docs explain why |
| 60-day wait for orphans | Some junk stays longer | Use `mo uninstall` manually |
| No undo | Gone is gone | Use dry-run first |
| English names only | Might miss localized apps | Falls back to bundle ID |
- All dependencies are pinned to specific versions. **Won't touch:**
- Regular security audits.
- No transitive dependencies with known CVEs.
- **Automated Releases**: Binaries are compiled and signed via GitHub Actions.
- **Source Only**: The repository contains no pre-compiled binaries.
--- - Your documents or media
- Password managers or keychains
**Our Commitment:** This document certifies that Mole implements industry-standard defensive programming practices and strictly adheres to macOS security guidelines. We prioritize system stability and data integrity above all else. - Files under `/etc`
- Browser history/cookies
*For security concerns or vulnerability reports, please open an issue or contact the maintainers directly.* - Git repos