temporal-cortex-datetime

• Outcome: Pass
• Latest audit: Sep 11, 2026 · 1:40 AM UTC
• Version: 0.9.1

Overview

This skill is a disclosed offline datetime helper, with the main caution being that it installs a third-party MCP binary during setup.

Install this only if you are comfortable running a third-party MCP binary. Prefer the pinned package path, verify the published checksums before first use, avoid running installation with elevated privileges, and use the documented Docker network isolation when you want stronger containment.

A.I.G

Vulnerability Patterns

• Remote Payload Retrieval and Execution: Fetches external code whose behavior can change after review
• Skill Instruction Hijacking: Alters the agent's session goals or safety constraints when the skill loads
• Agent Memory Poisoning: Writes attacker-controlled rules into memory that affect later sessions
• Embedded Malicious Code: Ships malicious scripts inside the skill and executes them locally
• Unauthorized Access and Privilege Escalation: Obtains permissions beyond the task's legitimate needs

Findings (1)

T03 · Remote Payload Retrieval and Execution

Error

• Location: SKILL.md:52

Finding

Installation Executes a Remotely Retrieved, Externally Maintained Binary

Content

View full analysis

Vulnerability Details

File Location: SKILL.md, lines 52-53
Vulnerability Type: Remote payload retrieval through an npm lifecycle script and third-party supply chain
Risk Level: High

text

1. `npx` resolves `@temporal-cortex/cortex-mcp` from the npm registry (one-time, cached locally after first download)
2. The postinstall script downloads the platform-specific binary from the [GitHub Release](https://github.com/temporal-cortex/mcp/releases/tag/mcp-v0.9.1) and verifies its SHA256 checksum against the embedded `checksums.json` — **installation halts on mismatch**

The associated package declaration appears at SKILL.md, lines 17-20:

yaml

install:
  - kind: node
    package: "@temporal-cortex/cortex-mcp@0.9.1"
    bins: [cortex-mcp]

An alternative installation method at SKILL.md, line 95 also builds from a remote, unpinned Git repository reference:

bash

docker build -t cortex-mcp https://github.com/temporal-cortex/mcp.git

Technical Analysis

The audited project does not contain the MCP server implementation or the installer responsible for retrieving its executable. Installation resolves an npm package and permits its postinstall lifecycle script to download a platform-specific binary from GitHub. Consequently, the code ultimately executed is outside the reviewed project and cannot be validated from the supplied files.

Pinning the npm package to version 0.9.1 reduces accidental version drift but does not eliminate supply-chain risk. The documented embedded checksums.json check establishes artifact integrity only relative to a checksum delivered through the same package or release process. If an attacker compromises the relevant npm publisher, release workflow, repository, or both the binary and its expected checksum, the check may still succeed.

The suggested independent SHA256SUMS.txt verification provides useful defense in depth, but the checksum is also retrie ...[truncated 2755 chars]

Remediation

View remediation

Remediation Suggestions

1. Vendor the reviewed MCP source or reviewed platform binaries into a controlled release process so that the executable being run is directly associated with the audited Skill version.
2. Avoid automatic network retrieval from npm lifecycle scripts. Install dependencies with lifecycle scripts disabled where feasible, then retrieve and verify the required executable through an explicit, separately reviewed process.
3. Publish cryptographically signed checksums or provenance attestations and verify them with a trusted public key distributed independently from npm and GitHub release artifacts.
4. Pin the Docker build to an immutable Git commit and, where possible, use a base image and resulting image identified by cryptographic digests rather than mutable tags or repository tips.
5. Require reproducible builds and compare locally produced binaries with published artifacts.
6. Run installation as an unprivileged user in an isolated environment with access limited to required directories. Do not use sudo for npm installation.
7. Enforce runtime containment using a read-only filesystem, no host volume mounts, dropped Linux capabilities, a non-root container user, resource limits, and --network=none.
8. Document the exact expected binary hashes for every supported platform in an immutable, reviewed Skill release, while still retaining signature verification.
9. Audit the external Rust source, npm installer, lifecycle scripts, release workflow, and Dockerfile before approving the dependency, because those components were absent from this audit artifact.

SkillSpector

Vulnerability Patterns

• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Data Exfiltration: External Transmission, Env Variable Harvesting, File System Enumeration
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access
• Supply Chain: Unpinned Dependencies, External Script Fetching, Obfuscated Code
• Excessive Agency: Unrestricted Tool Access, Autonomous Decision Making, Scope Creep

Findings (1)

Rp1

Medium

• Category: MCP Rug Pull
• Confidence: 70% confidence

Finding

npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Content

No source excerpt is available for this finding.

Static analysis

No suspicious patterns detected.