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Security audit

HTML to Image

Security checks for vulnerabilities and agentic risk

Overview

The image workflow makes sense, but its setup runs unverified remote code and omits documented changes to other agents’ installed skills.

Review and preinstall a verified CLI version before enabling this skill. Check and control its documented startup skill synchronization, which can affect other agent installations. Send only HTML/CSS you intend OOMOL and the rendering provider to process. Remote installer contents were unavailable, so their exact behavior remains uncertain.

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
Vulnerability Patterns
  • Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Output HandlingUnvalidated Output Injection, Cross-Context Output, Unbounded Output
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Findings (5)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
97% confidence
Finding

The supplied chunk contains only a login command, with no HTML processing, image generation, or related data retrieval. Authentication could be a supporting implementation detail if its connection to html2img.com were established, but the supplied content provides no such connection and does not implement the declared purpose.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
93% confidence
Finding

The supplied chunk performs remote installer execution rather than an HTML-to-image operation. Installation could be a supporting implementation detail, but the provided content does not establish that this installer supports html2img.com or the declared workflow. The remote script's contents and downstream effects are not available for assessment.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

The fallback pipes a remotely fetched, unpinned script directly into Bash without integrity verification or review; the PowerShell alternative has the same execution pattern. If the distribution endpoint or publishing pipeline is compromised, attacker-controlled code runs with the agent process's permissions, potentially exposing local files and credentials; restricting this to missing-CLI recovery reduces frequency but not impact.

Content

Scanner excerpt · SKILL.md (reported line 56)May include surrounding context.

The action workflow lacks a privacy warning about sending HTML and CSS to third-party services.

Medium
Category
Output Handling
Confidence
91% confidence
Finding

Raw HTML and CSS may contain confidential content, embedded tokens, or personal data, and this workflow sends the payload through OOMOL to an external rendering service without a sensitive-data check. The external-service purpose is disclosed, which reduces surprise, but the broad instruction to use this skill for any HTML-to-image request can still cause unintended disclosure of private input.

Content

No source excerpt is available for this finding.

Autonomous Decision Making

Medium
Category
Excessive Agency
Confidence
80% confidence
Finding

Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.

Content

Scanner excerpt · SKILL.md (reported line 77)May include surrounding context.

md
- **`OOMOL_INSUFFICIENT_CREDIT`** — OOMOL billing stop. Recharge at `https://console.oomol.com/billing/token-recharge` before retrying.

- **HTTP 402 without `OOMOL_INSUFFICIENT_CREDIT`** — the third-party account itself has no active plan or credit. Report the provider error message as is; do not ask the user to recharge OOMOL.

## Resources