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Security audit

Slack Block Kit

Security checks for vulnerabilities and agentic risk

Overview

This skill is a coherent Slack Block Kit helper that can generate and post Slack messages, with its Slack API/token use disclosed and aligned to that purpose.

Install only for workspaces where the agent is allowed to compose or send Slack messages. Confirm the destination channel, thread, and content before using the direct Slack API posting path, and keep Slack bot tokens in configured secrets rather than pasted into chat or logs.

A.I.G

Vulnerability Patterns
  • Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
  • Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
  • Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
  • Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
  • Unauthorized Access and Privilege EscalationObtains permissions beyond the task's legitimate needs

SkillSpector

Vulnerability Patterns
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • Trigger AbuseOverly Broad Trigger, Shadow Command Trigger, Keyword Baiting Trigger
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Findings (12)

Ae1

High
Category
analysis-evasion
Content
- `samples/blocks/agents/plan.json`
Confidence
100% confidence
Finding
Referenced artifact was not completely inspected

Ae1

High
Category
analysis-evasion
Content
- `samples/blocks/contact_card.json`
Confidence
100% confidence
Finding
Referenced artifact was not completely inspected

External Transmission

Medium
Category
Data Exfiltration
Content
For raw Slack Block Kit JSON, use Slack `chat.postMessage` directly. The OpenClaw `message` tool schema accepts `presentation`, not a top-level raw `blocks` array.

```bash
curl -s -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d "$(jq -n \
Confidence
60% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Vague Triggers

Medium
Confidence
94% confidence
Finding
The skill enables implicit invocation while using a very broad default prompt about creating Slack Block Kit messages. Because many ordinary user requests about Slack formatting, messages, tables, buttons, or layouts could match this language, the agent may invoke the skill unexpectedly and cause actions or message generation outside the user's precise intent. In a Slack-integrated context, this increases the risk of unintended message composition or downstream posting workflows.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

External Transmission

Medium
Category
Data Exfiltration
Content
[
  {
    "type": "image",
    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/beagle.png",
    "alt_text": "Example status image",
    "title": {
      "type": "plain_text",
Confidence
50% confidence
Finding
Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.

Static analysis

No suspicious patterns detected.