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Security audit

Paperless-ngx

Security checks for vulnerabilities and agentic risk

Overview

Review is warranted because setup directly executes downloaded code and profile actions may expose an API token despite assurances otherwise.

Review and explicitly approve CLI installation using a verified, pinned release. Use a narrowly permissioned Paperless-ngx account and understand that OOMOL mediates document access. Avoid profile actions until API tokens are filtered before reaching the agent. The supplied files establish these concerns but do not establish malicious intent or verify external runtime behavior.

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 (5)

Description-Behavior Mismatch

High
Category
MCP Tool Poisoning
Confidence
97% confidence
Finding

The supplied command performs remote software installation rather than any visible Paperless-ngx operation. Nothing in the supplied content establishes this installer as a supporting dependency for Paperless-ngx. The downloaded script is not provided, so its further behavior cannot be assessed.

Content

No source excerpt is available for this finding.

External Script Fetching

High
Category
Supply Chain
Confidence
98% confidence
Finding

The curl-to-bash command immediately executes mutable remote content without a pinned version or independent integrity verification; the PowerShell alternative has the same weakness. A compromised installer host or release pipeline could execute attacker-controlled code with the agent's local privileges, although there is no evidence that the current installer is malicious.

Content

Scanner excerpt · SKILL.md (reported line 193)May include surrounding context.

Profile actions return a raw API token despite the stated guarantee that tokens are never handled.

Medium
Category
Excessive Agency
Confidence
97% confidence
Finding

The documented get_profile and update_profile responses include the API token, contradicting the assurance that the agent never handles raw tokens. If those responses reach the agent as described, credentials can enter model context, transcripts, or downstream outputs; redaction from logs alone does not prevent this exposure.

Content

No source excerpt is available for this finding.

Fallback setup executes downloaded installer code without a user warning or confirmation.

Medium
Category
Output Handling
Confidence
96% confidence
Finding

The missing-CLI fallback directs installation without explicit approval, extending a Paperless-ngx request into local code execution and environment modification. The confirmation rules only cover tagged connector actions, so they do not clearly protect this setup path; the error-triggered condition reduces frequency but not the potential consequence.

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 214)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