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Security audit

Memberstack

Security checks for vulnerabilities and agentic risk

Overview

Memberstack changes require approval, but setup runs unverified downloads and omits broader changes the CLI can make to your agents.

Review the CLI installation separately before allowing automatic setup. Memberstack data passes through OOMOL; confirm exact changes, especially deletion and Stripe cleanup. To prevent startup skill synchronization, the publisher documents OO_SKILLS_SYNC_DISABLED=1 in its [command reference](https://github.com/oomol-lab/oo-cli/blob/main/docs/commands.md#environment-variables). Remote installer contents and hosted connector behavior remain unverified.

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 code executes an Oomol-hosted installer and contains no Memberstack API calls or data operations. No connection is established between this installation and the declared Memberstack functionality, so this is an undeclared capability involving an inconsistent resource. The remote script's contents and further effects cannot be determined from the supplied chunk.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

Piping the HTTPS response directly into bash executes mutable remote content without an inspection or integrity-verification step. Although the domain belongs to the CLI provider and installation supports the Memberstack workflow, compromise of the distribution endpoint could expose local files and credentials or allow persistent system changes under the user's privileges.

Content

Scanner excerpt · SKILL.md (reported line 62)May include surrounding context.

The fallback setup executes downloaded installation scripts without warning about remote code execution or system changes.

Medium
Category
Output Handling
Confidence
94% confidence
Finding

The fallback directs the agent to execute remotely downloaded shell or PowerShell code without integrity verification or explicit approval for local software installation. A compromised installer source could execute arbitrary code with the invoking user's privileges; the missing-CLI condition limits exposure but does not make execution safe.

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 83)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