# Server Side

> Server-side vulnerability testing - SSRF, HTTP Request Smuggling, Path Traversal, File Upload, Insecure Deserialization, and Host Header injection.

- Skill: `transilienceai/server-side` (Agent Skill, multi-file: 50 files)
- Install (CLI): `npx skillmds add transilienceai/server-side`
- Raw SKILL.md: https://api.skillmd.com/api/skills/transilienceai/server-side/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: transilienceai (https://skillmd.com/u/transilienceai)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/transilienceai/server-side

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# Server-Side

Test for server-side vulnerabilities that allow unauthorized access, RCE, or data exfiltration.

## Techniques

| Type | Key Vectors |
|------|-------------|
| **SSRF** | Internal service access, cloud metadata, protocol smuggling |
| **HTTP Smuggling** | CL.TE, TE.CL, TE.TE, CL.0, H2.CL, h2c, multi-layer proxy chains, connection pooling desync |
| **Path Traversal** | Directory traversal, null bytes, encoding bypass |
| **File Upload** | Extension bypass, content-type manipulation, polyglot files |
| **Deserialization** | Java, PHP, Python, .NET gadget chains |
| **Host Header** | Password reset poisoning, cache poisoning, routing-based SSRF |
| **CUPS / cups-browsed** | CVE-2024-47076/47175/47176/47177 — UDP browse → IPP injection → PPD injection → foomatic-rip RCE (see `skills/infrastructure/reference/scenarios/network-recon/cups-browsed-rce.md`) |

## Workflow

1. Identify server-side processing points
2. Test for vulnerability class indicators
3. Bypass protections (WAF, allowlists, encoding filters)
4. Demonstrate impact (file read, RCE, internal access)
5. Capture evidence with PoC

## Reference

- `reference/scenarios/ssrf/*.md` - SSRF techniques and labs
- `reference/http-request-smuggling*.md` - Smuggling techniques
- `reference/scenarios/path-traversal/*.md` - Path traversal bypass methods
- `reference/file-upload*.md` - File upload exploitation
- `reference/insecure-deserialization*.md` - Deserialization attacks
- `reference/http-host-header*.md` - Host header injection
- `skills/infrastructure/reference/scenarios/network-recon/cups-browsed-rce.md` - CUPS RCE chain (CVE-2024-47076/175/176/177); ipptool false positives vs libcups runtime parser; ippserver Python lib version-1.1 hardcode bug