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Security audit

ytapi-youtube-transcript

Security checks for vulnerabilities and agentic risk

Overview

This skill does what it claims, but its setup flow has the agent create an external account and persist an API key for future sessions, which deserves user review.

Install only if you are comfortable using YTAPI as a third-party service. Prefer creating the YTAPI account yourself and pasting an API key, and store the key in a proper secrets manager or session-scoped environment variable instead of letting the agent persist it broadly for all future shells.

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
  • Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep
  • Tool MisuseTool Parameter Abuse, Chaining Abuse, Unsafe Defaults
  • Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
  • Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Findings (11)

Ssd 3

High
Category
Not specified by scanner
Confidence
96% confidence
Finding

The instructions tell the agent to solicit sensitive information including an API key, email address, and a 6-digit verification code, then use those values to create and bind a third-party account. Handling both authentication factors and long-lived credentials materially increases the chance of secret leakage, account misuse, or unauthorized persistence.

Content

No source excerpt is available for this finding.

Ssd 3

High
Category
Not specified by scanner
Confidence
95% confidence
Finding

The skill saves signup tokens and API-key-bearing responses into temporary files, then later extracts and persists the resulting API key. Temporary files in shared or weakly isolated environments can be read by other processes, retained in logs or snapshots, or mishandled before cleanup occurs.

Content

No source excerpt is available for this finding.

Ssd 3

High
Category
Not specified by scanner
Confidence
97% confidence
Finding

The skill explicitly directs persistent storage of the user's API key so it is automatically available in future sessions and non-interactive shells. Long-lived ambient credentials are dangerous because they may be unintentionally reused by unrelated tasks, exposed to downstream tools, or harvested after host compromise.

Content

No source excerpt is available for this finding.

Tool Parameter Abuse

High
Category
Tool Misuse
Confidence
85% confidence
Finding

Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Content

Scanner excerpt · references/auth-setup.md (reported line 94)May include surrounding context.

md
2. Check it in the current session without printing it, for example
   `test -n "$YTAPI_API_KEY" && echo set`. If the session must be reloaded to
   see it, reload it or tell the user.
3. Delete the temporary files: `rm -f /tmp/ytapi-signup.json /tmp/ytapi-verify.json`.

The user can sign in at https://ytapi.dev/auth/login?utm_source=skill with the same email to
see usage, manage keys and buy credits.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
92% confidence
Finding

The skill explicitly permits creating a third-party YTAPI account using the user's email, but it does not present a clear privacy/data-sharing warning at the point of collection or explain what data will be sent to the external service. This creates a real privacy and consent risk because the agent may transmit personal data to an external provider without sufficiently informed user approval.

Content

No source excerpt is available for this finding.

External Transmission

Medium
Category
Data Exfiltration
Confidence
86% confidence
Finding

The skill sends user-supplied video identifiers or URLs and an API credential to an external service at api.ytapi.dev. While external API use is expected for this skill, it still represents a real data-transmission boundary and can expose user inputs, usage metadata, and potentially sensitive URLs to a third party if invoked without clear disclosure.

Content

Scanner excerpt · SKILL.md (reported line 43)May include surrounding context.

Get a transcript (1 credit)

bash
curl -s "https://api.ytapi.dev/v1/transcripts?video_id=VIDEO_ID_OR_URL&format=text" \
  -H "Authorization: Bearer $YTAPI_API_KEY"

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
92% confidence
Finding

The file instructs the agent to make YTAPI_API_KEY persist across future sessions and non-interactive shells without presenting any user-facing warning about the security implications. Persisting secrets silently can expose them to other processes, future tasks, or users sharing the same environment.

Content

No source excerpt is available for this finding.

Context-Inappropriate Capability

Medium
Category
Not specified by scanner
Confidence
94% confidence
Finding

The skill directs the agent to help create a third-party YTAPI account and then persist the resulting credential for later reuse. That exceeds the narrow transcript-retrieval function and expands the agent's authority into account provisioning and long-term secret management, increasing the blast radius if the environment is shared or later compromised.

Content

No source excerpt is available for this finding.

Missing User Warnings

Medium
Category
Not specified by scanner
Confidence
93% confidence
Finding

The skill asks the user for an email address and transmits it to an external service to create an account, but it does not clearly warn the user that their personal data will be sent off-platform. This creates privacy and consent risk, especially because account creation is optional and beyond the core transcript function.

Content

No source excerpt is available for this finding.

External Transmission

Medium
Category
Data Exfiltration
Confidence
86% confidence
Finding

This command sends the user's email address to an external service endpoint for signup. External transmission of personal data is risky when not minimized, clearly disclosed, and consented to, particularly since this action supports account creation rather than the core retrieval function.

Content

Scanner excerpt · references/auth-setup.md (reported line 37)May include surrounding context.

to request in one step.

bash
curl -s -X POST https://ytapi.dev/api/agent/signup \
  -H "Content-Type: application/json" \
  -d '{"email": "USER_EMAIL"}' \
  -o /tmp/ytapi-signup.json

External Transmission

Medium
Category
Data Exfiltration
Confidence
93% confidence
Finding

This command transmits a signup token and user-provided verification code to the external service, completing an authentication flow on the user's behalf. Sending active authentication material off-platform is sensitive because compromise of the agent environment or logs could enable account takeover or unauthorized account binding.

Content

Scanner excerpt · references/auth-setup.md (reported line 60)May include surrounding context.

bash
TOKEN=$(sed -n 's/.*"signup_token":"\([^"]*\)".*/\1/p' /tmp/ytapi-signup.json)
curl -s -X POST https://ytapi.dev/api/agent/verify \
  -H "Content-Type: application/json" \
  -d "{\"signup_token\": \"$TOKEN\", \"code\": \"CODE\"}" \
  -o /tmp/ytapi-verify.json

Static analysis

No suspicious patterns detected.