T03 · Remote Payload Retrieval and Execution
Error
- Location
README.md:12- Finding
Mutable Remote Script Download Without Integrity Verification
- Content
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- Remediation
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Security audit
Hacker News Poster
Security checks for vulnerabilities and agentic risk
Overview
This skill appears to do what it claims, but it handles Hacker News credentials and session cookies and includes a risky unpinned script-download path.
Review before installing. Use this only with an account you are comfortable posting from through an agent, avoid putting the password on the command line, protect or delete the cookie file after use, and prefer the packaged ClawHub install over the README's raw GitHub curl command unless the downloaded script is pinned and verified.
Vulnerability Patterns
- Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
- Insecure Skill Coding PracticesFinds exploitable flaws such as hardcoded secrets or command injection
- 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
- Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally
Findings (3)
T09 · Insecure Skill Coding Practices
Warning
- Location
scripts/hn.py:14- Finding
Session Cookies Persisted Without Explicit Owner-Only Permissions
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T09 · Insecure Skill Coding Practices
Warning
- Location
scripts/hn.py:143- Finding
Password Accepted Through a Command-Line Argument
- Content
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` or `-p `. 2. The complete command is recorded in shell history, execution telemetry, an agent transcript, or an accessible process listing. 3. A local user, administrator, monitoring integration, or log reader retrieves the password. 4. The attacker authenticates directly to Hacker News using the exposed reusable credential. ### Impact Assessment The exposed value is the user's Hacker News password rather than a narrowly scoped application token. Successful exploitation can therefore enable account takeover, including future logins after the local session cookie expires. The practical scope includes posting, commenting, profile modification, and any other action permitted by the compromised Hacker News account. No operating-system privilege e ...[truncated 34 chars]- Remediation
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Vulnerability Patterns
- Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
- MCP Least PrivilegeUnderdeclared Capability, Wildcard Permission, Missing Permission Declaration
- Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
- Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
- Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Findings (4)
Missing User Warnings
Medium
- Category
- Not specified by scanner
- Confidence
- 90% confidence
- Finding
The README instructs users to place Hacker News credentials in environment variables but provides no warning about their sensitivity, storage lifetime, or leakage risks. In agent and CI environments, environment variables are commonly exposed to subprocesses, logs, crash reports, shell history, or debugging output, which can lead to account compromise if the credentials are reused or insufficiently protected.
- Content
Undeclared Tool Scope
Medium
- Category
- MCP Least Privilege
- Confidence
- 95% confidence
- Finding
The skill declares no explicit tool scope or permission boundaries even though it clearly requires access to environment secrets and network capabilities to authenticate and post to Hacker News. Without declared restrictions, an agent runtime may over-grant access or make the skill callable in broader contexts than intended, increasing the risk of credential misuse, unintended posting, or abuse of stored session cookies.
- Content
Missing User Warnings
Medium
- Category
- Not specified by scanner
- Confidence
- 91% confidence
- Finding
The script persists authenticated Hacker News session cookies to a predictable local file in the user's home directory and reloads them automatically on future runs. If that file is readable by other local users, copied into backups, or left on shared systems, an attacker could reuse the session and act as the victim account without knowing the password.
- Content
Missing User Warnings
Medium
- Category
- Not specified by scanner
- Confidence
- 86% confidence
- Finding
cmd_login reads HN_USERNAME and HN_PASSWORD from environment variables, which are sensitive inputs that may be exposed through shell history, process environments, or misconfigured tooling. The code mentions the variables in an error message but does not provide any safety warning or disclosure about the risks of supplying credentials this way.
- Content