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Security audit

WaiverFile

Security checks for vulnerabilities and agentic risk

Overview

The WaiverFile read functions fit their purpose, but setup can execute unverified downloaded code and introduce broader changes to installed agent skills without clear user control.

Review and approve CLI installation separately before using the skill. Confirm that OOMOL may process your waiver requests and manage the connected credentials. Review the CLI's automatic skill synchronization and disable it if unwanted. The external installer and runtime implementation are not bundled, so their exact behavior remains outside this artifact review; no 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
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
  • 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
Findings (5)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
98% confidence
Finding

The supplied code runs an Oomol-hosted installation script rather than performing a WaiverFile operation. Nothing in the provided chunk establishes this installation as a supporting dependency for WaiverFile access. The downloaded script is not supplied, so its specific effects cannot be determined.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping a mutable remote installer directly into Bash executes its contents without prior verification; the PowerShell alternative has the same issue. HTTPS protects transport but does not prevent a compromised publisher or distribution endpoint from serving code that accesses local files, credentials, or other resources available to the user.

Content

Scanner excerpt · SKILL.md (reported line 60)May include surrounding context.

The setup workflow executes downloaded installer scripts without warning about the system-integrity implications.

Medium
Category
Output Handling
Confidence
93% confidence
Finding

The fallback directs the agent to execute downloaded installation code without explaining the local code-execution implications or requiring explicit approval for installation. Although conditional on a missing CLI, this can turn a read-only WaiverFile request into arbitrary code execution with the invoking user's permissions if the installer source is compromised.

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 81)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

External Transmission

Medium
Category
Data Exfiltration
Confidence
50% 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 86)May include surrounding context.

md
## Resources

- WaiverFile homepage: https://www.waiverfile.com
- API documentation: https://api.waiverfile.com/swagger/ui/index