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Security audit

TheirStack

Security checks for vulnerabilities and agentic risk

Overview

The searches match the stated purpose, but setup executes unverified downloaded code and leaves broader changes to other agent skills unexplained.

Review and install the CLI separately before allowing automated use. Its documented OO_SKILLS_SYNC_DISABLED setting can prevent startup deployment of other agent skills; see the [command reference](https://github.com/oomol-lab/oo-cli/blob/main/docs/commands.md). Connect only the intended TheirStack account and consider that queries pass through OOMOL. The remote installers and hosted credential handling were not verified; 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
  • 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 installs software from an Oomol domain rather than searching or reading TheirStack data. No connection to TheirStack or need for this installer is established, so this is an undeclared capability and inconsistent resource access, not an evidenced supporting implementation detail. The downloaded script's further behavior 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

The command pipes a live network response directly into Bash without pinning or independently verifying the script; the PowerShell alternative uses the same fetch-and-execute pattern. If the distribution endpoint or delivery pipeline is compromised, an attacker could execute code with the invoking user's privileges, potentially accessing local credentials or modifying files; HTTPS alone does not establish script integrity.

Content

Scanner excerpt · SKILL.md (reported line 58)May include surrounding context.

Fallback setup executes downloaded installation scripts without warning the user about remote code execution or system changes.

Medium
Category
Output Handling
Confidence
95% confidence
Finding

A missing CLI triggers instructions to execute a remote installer without explicitly obtaining approval for local software installation and arbitrary code execution. Although conditional on a setup failure, this expands a data-reading request into potentially persistent system changes under the executing user's privileges; the declared Bash allowlist may restrict execution but is not an installation-consent safeguard.

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 79)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