slack
4 findings (2 high, 2 medium), mainly data exfiltration, social engineering, unauthorized tool use. Most recent scan 2026-02-07.
This Slack integration skill presents SIGNIFICANT SECURITY CONCERNS due to its architecture of routing all Slack API requests through a third-party gateway (maton.ai). The primary risks are: (1) Data exfiltration - all Slack workspace data flows through an external service with no visibility into logging or storage practices, (2) Credential exposure - the gateway has persistent access to OAuth tokens and can perform any Slack operation, (3) Misleading description - the skill appears to be a standard Slack integration but actually introduces a third-party intermediary with full workspace access. Additional concerns include hardcoded API key patterns in documentation, a missing referenced Python file (Slack.py), and lack of transparency about the trust model. While the skill may be functional, the security implications of using a third-party OAuth proxy for enterprise Slack workspaces are severe. The skill is NOT RECOMMENDED for production use without significant security enhancements and clear disclosure of the proxy architecture.
Scanner's overall assessment (LLM analyzer)
Second scanner: NVIDIA SkillSpector
Independent static run, no language model, over the same files as the Cisco scan above. How the two scanners compare across the whole corpus: Two scanners, one corpus.
What this skill does
Slack API integration with managed OAuth. Send messages, manage channels, search conversations, and interact with Slack workspaces. Use this skill when users want to post messages, list channels, get user info, or automate Slack workflows.
- Package
- 2 files, 8.0 KB
- SKILL.md
- 699 words, 12+ sections
- Code
- None. Instructions only.
- Compatibility
- Requires network access and valid Maton API key
SKILL.md covers: Slack · Quick Start · Post a message to a channel · Base URL · Authentication · Getting Your API Key · Connection Management · List Connections · Create Connection · Get Connection · Delete Connection · Specifying Connection
Findings
HIGH Hardcoded API Key Exposure Risk in Documentation Data Exfiltrationllm
The skill documentation contains multiple examples showing 'YOUR_API_KEY' placeholders and instructs users to set MATON_API_KEY as an environment variable. While the examples use placeholders, the skill's reliance on a third-party API gateway (maton.ai) for OAuth token management creates a credential exposure risk. All Slack API requests are proxied through gateway.maton.ai with the user's API key, meaning the gateway has access to both the Maton API key and the OAuth tokens for Slack workspaces. This creates a single point of failure where compromise of the gateway or API key leads to full Slack workspace access.
SKILL.md
```bash
export MATON_API_KEY="YOUR_API_KEY"
```
All requests require: `Authorization: Bearer YOUR_API_KEY`
Base URL: `https://gateway.maton.ai/slack/{method}`HIGH Third-Party OAuth Proxy Creates Data Exfiltration Risk Data Exfiltrationllm
The skill routes all Slack API requests through a third-party gateway (gateway.maton.ai) that 'automatically injects your OAuth token'. This architecture means all Slack workspace data (messages, channels, users, files) flows through an external service controlled by maton.ai. Users have no visibility into what data the gateway logs, stores, or transmits. The gateway has persistent access to OAuth tokens and can perform any Slack API operation on behalf of the user. This creates significant data exfiltration and privacy risks, especially for enterprise Slack workspaces containing sensitive business communications.
SKILL.md
Base URL: `https://gateway.maton.ai/slack/{method}`
'The gateway proxies requests to slack.com and automatically injects your OAuth token.'
All API calls go through: POST 'https://gateway.maton.ai/slack/api/chat.postMessage'MEDIUM Misleading Skill Description Omits Third-Party Dependency Social Engineeringllm
The skill description states 'Slack API integration with managed OAuth' but fails to clearly disclose that this is not a direct Slack integration. Instead, all API requests are proxied through a third-party service (maton.ai) that manages OAuth tokens on behalf of users. The description makes it sound like a standard Slack integration, but the architecture introduces significant trust assumptions and security implications that are not apparent from the description alone. Users may not realize they're granting a third party full access to their Slack workspace.
SKILL.md
Description: 'Slack API integration with managed OAuth. Send messages, manage channels, search conversations, and interact with Slack workspaces.'
Actual implementation: All requests proxied through https://gateway.maton.ai with third-party OAuth token managementMEDIUM Missing Referenced Script File Creates Tool Execution Risk Unauthorized Tool Usellm
The skill instructions reference a file 'Slack.py' that is not found in the package. This creates ambiguity about how the skill is intended to be used. If users attempt to locate or create this missing file, they may introduce security vulnerabilities. The missing file could also indicate incomplete packaging, supply chain issues, or that the skill relies on external dependencies not included in the package. Without the actual implementation, it's impossible to verify what operations the Python script performs or whether it properly validates inputs.
Referenced Files: Slack.py (not found)
No script files found in package, but instructions reference Python implementationWhat is in the package
| File | Kind | Size |
|---|---|---|
LICENSE.txt | doc | 1.0 KB |
SKILL.md | doc | 7.0 KB |
External hosts referenced
api.slack.com ctrl.maton.ai gateway.maton.ai maton.ai connect.maton.ai docs.slack.dev
Hostnames that appear in the skill's files. Referencing a host is not a finding; compare against the findings above and the skill's stated purpose.
Environment variables referenced
MATON_API_KEY
Package contents recorded 2026-10-22. The scan above ran against the version current at scan time; the two can differ if the skill has since been updated.
What we checked
- Static analyzer. Pattern rules over SKILL.md and bundled files: known-bad commands, exfiltration URLs, secrets, obfuscation.
- Llm analyzer. A language model reads the skill and reports intent-level issues the rules cannot express.
- Meta analyzer. A second model pass that validates, deduplicates and re-scores the other analyzers' findings.
What we did not check
- Runtime behaviour. The skill was not executed; findings come from reading its files.
- Anything fetched at install or run time, including remote scripts, package dependencies, and URLs the skill tells the agent to open.
- Content the analyzers cannot read: images, binaries, and some non-English text.
- Known scanner bypass classes. See the methodology and limitations page.
Sources
- Repository: https://clawhub.ai/skills/slack-api
- Raw scan result: slack-scan.json
- Badge for your README:
 - Request a re-scan