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Security audit

Certn

Security checks for vulnerabilities and agentic risk

Overview

The Certn functions match the stated purpose, but first-time setup can execute unverified downloaded code without clear user approval.

Review and install the CLI separately before using this skill, checking its integrity and any bundled skill changes. Use a narrowly scoped Certn connection and understand that OOMOL mediates sensitive records. The remote installers could not be inspected; their exact changes remain unknown. No artifact-backed malicious behavior was established.

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 (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
99% confidence
Finding

The supplied command performs remote script execution rather than searching or reading Certn data. No Certn interaction or dependency relationship is shown that would establish this installation as a supporting implementation detail. The downloaded script's contents are not supplied, so its further behavior cannot be assessed.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
99% confidence
Finding

The command pipes a remotely fetched, unpinned script directly into Bash; the Windows alternative similarly evaluates downloaded code immediately. If the distribution endpoint or release pipeline is compromised, arbitrary code could execute with the agent process's privileges and access local files or credentials; HTTPS alone does not establish artifact integrity.

Content

Scanner excerpt · SKILL.md (reported line 64)May include surrounding context.

First-time setup executes downloaded installer scripts without warning about remote code execution or local system changes.

Medium
Category
Output Handling
Confidence
96% confidence
Finding

When the CLI is missing, the skill directs installation without requiring user approval or explaining that downloaded code will execute and may modify the local system. Restricting this to first-time setup reduces frequency, but a request to read Certn data does not inherently authorize software installation.

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 85)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