Security audit

billboardbug

Security checks for vulnerabilities and agentic risk

Overview

This skill is a disclosed BillboardBug API workflow for creating and verifying public billboard deals and social posts, with a few guardrail and wording gaps users should notice.

Install only if you intend to let an agent publish BillboardBug deals and chirps under your account. Keep the API key in the environment only, review every create/update/delete action before it happens, avoid paid featured placement unless explicitly approved, and treat the receipt wording about deal IDs as ambiguous.

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
Tool MisuseTool Parameter Abuse, Chaining Abuse, Unsafe Defaults
MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access

Findings (3)

Tool Parameter Abuse

High

Category: Tool Misuse
Confidence: 81% confidence
Finding: The skill exposes a destructive endpoint (DELETE /posts/{id}) with no documented guardrails equivalent to the creation confirmation flow. In an agent setting, a malicious or ambiguous user prompt could induce deletion of arbitrary posts accessible to the account, causing unauthorized content removal or business disruption.
Content: Scanner excerpt · SKILL.md (reported line 224)May include surrounding context.
-> {"id":"", ...}

text
Edit: `PUT /posts/{id}`. Delete: `DELETE /posts/{id}`. Comment: include `parentPostId`. Chirp fields (`PostRequest`): `isActive` (required), `text`, `imageId`, `videoId`, `videoUrl`, `parentPostId`, `isMature`. Supply at least one of text/imageId/videoId. Read back with

External Transmission

Medium

Category: Data Exfiltration
Confidence: 60% confidence
Finding: Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
Content: Scanner excerpt · SKILL.md (reported line 108)May include surrounding context.
Generate (optional):

bash
curl -s https://east-us-api.billboardbug.com/ai/image \ -H "X-Api-Key: $BILLBOARDBUG_API_KEY" -H "X-Version: 1" -H "Content-Type: application/json" \ -d '{"prompt":"Realistic photo of a cozy neighborhood coffee shop storefront, morning light","aiProvider":5,"width":640,"height":373}' \ > ai.json

Intent-Code Divergence