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Security audit

Browser Use

Security checks for vulnerabilities and agentic risk

Overview

Browser Use actions require approval, but the setup path executes unverified remote code and can introduce additional agent skills without explaining those changes.

Review and install the CLI separately before using this skill. Decide whether to allow its additional agent skills; upstream documents OO_SKILLS_SYNC_DISABLED=1 to disable startup synchronization. OOMOL mediates the connected account and task requests, so use an appropriately scoped account and review each task payload. The remote installer contents and resulting release were not verified.

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
  • MCP Tool PoisoningHidden Instructions, Unicode Deception, Parameter Description Injection
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Findings (4)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
97% confidence
Finding

The supplied chunk installs software from a different service and contains no Browser Use operations or evidence that this installation supports the declared service. Remote installer execution is a materially different capability from the described browser-data tasks. The downloaded script's contents are not supplied, so its further behavior cannot be determined.

Content

No source excerpt is available for this finding.

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
94% confidence
Finding

The supplied code only invokes a CLI login command. It contains no Browser Use operations or evidence connecting this authentication step to browser-use.com. Although authentication can be a supporting implementation detail, the supplied chunk does not establish that relationship and instead presents a materially different function.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

The setup command pipes a mutable remote script directly into Bash without pinning or independently verifying the downloaded content; the PowerShell alternative uses the same download-and-execute pattern. Compromise of the distribution endpoint or release process could execute attacker-controlled code with the invoking user's privileges, exposing local files and credentials. Limiting this behavior to missing-CLI errors reduces exposure but does not remove the supply-chain risk.

Content

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

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