hunt-ssti
Hunt server-side template injection (SSTI) across Jinja2 (Flask/Django), Twig (Symfony), Freemarker (Java), ERB (Rails), Spring, Velocity, Mako, Thymeleaf, Smarty. Detection probes use double-curly and dollar-curly math expressions evaluated server-side. Once an engine is fingerprinted, escalate to RCE via the engine-specific class-walker, callback-registrar, or Execute-utility patterns documented in disclosed reports. Detection patterns: error messages reveal engine, blank or numeric eval reveals expression mode. Targets: email templates, PDF/report generators, CMS preview features, error pages with user input. Use when hunting RCE via template rendering, when content shows engine fingerprints, when finding endpoints that compose strings with user input before render.
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Critical
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Security
3 findings: 1 critical severity, 1 high severity, 1 medium severity. Installing this skill is not recommended: please review these findings carefully if you do intend to do so.
E006: Malicious code pattern detected in skill scripts.
What this means
Detected high-risk code patterns in the skill content — including its prompts, tool definitions, and resources — such as data exfiltration, backdoors, remote code execution, credential theft, system compromise, supply chain attacks, and obfuscation techniques.
Why it was flagged
This document is an explicit offensive-techniques guide detailing SSTI exploitation and provides ready-to-run payloads and instructions to achieve remote command execution, metadata/credential exfiltration, and evasion—clearly intended for malicious exploitation.
W007: Insecure credential handling detected in skill instructions.
What this means
The skill handles credentials insecurely by requiring the agent to include secret values verbatim in its generated output. This exposes credentials in the agent’s context and conversation history, creating a risk of data exfiltration.
Why it was flagged
The skill explicitly instructs payloads that exfiltrate sensitive data (e.g., AWS metadata/http://169.254.169.254/... → "cloud creds") and tells the agent to fetch and embed CSRF tokens in requests, which requires the LLM to read and include secret values verbatim in its outputs/requests.
W013: Attempt to modify system services in skill instructions.
What this means
The skill prompts the agent to compromise the security or integrity of the user’s machine by modifying system-level services or configurations, such as obtaining elevated privileges, altering startup scripts, or changing system-wide settings.
Why it was flagged
The skill explicitly tells the agent to "escalate straight to RCE" and supplies concrete OS-command-executing payloads (e.g., os.popen, freemarker Execute, metadata exfiltration), which encourages executing arbitrary OS commands on systems that render the templates and could lead the agent to run those commands on its own host.
- Repository
- elementalsouls/Claude-BugHunter
- Commit
6b9c96e
- Audited
- Security analysis
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