Server-Side Template Injection

Server-Side Template Injection is a Quality skill for Claude Code, published by CyberStrikeus in CyberStrike.

1.7K stars269 forkson CyberStrikeus/CyberStrikeAdded 2026/08/12+4% in starsRepository updated 2026/08/12

aiai-agentai-securitybug-bountycybersecuritydevsecopsethical-hackinghackinghacking-toolllmmcpmcp-servermitre-attackoffensive-securityowasppenetration-testingpentestred-teamsecuritysecurity-tools

Install in seconds

Install Server-Side Template Injection

Copy Server-Side Template Injection into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/CyberStrikeus/CyberStrike/tree/main/.cyberstrike/skill/attack-ssti ~/.claude/skills/attack-ssti

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/CyberStrikeus/CyberStrike.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: .cyberstrike/skill/attack-ssti/SKILL.md in CyberStrikeus/CyberStrike
Installs to: ~/.claude/skills/attack-ssti
Collection: One of 51 skills cataloged from this repository
Category: Quality — 1354 skills

What Server-Side Template Injection does

Server-Side Template Injection detects SSTI, fingerprints template engines, and tests for code execution in server-rendered inputs. Use it when a web app may evaluate user-controlled template syntax.

Server-Side Template Injection is cataloged under Quality on DirSkills. Server-Side Template Injection comes from a repository tagged ai, ai-agent, ai-security, bug-bounty and cybersecurity.

Documentation

README

Excerpt

Server-Side Template Injection (SSTI)

Objective

Detect and exploit server-side template injection to achieve code execution on the server.

Testing Methodology

Phase 1: Detection

# Automated SSTI detection across 7 engines
attack_script ssti_tester "https://TARGET/search?q=FUZZ" --param q --json-output

# Quick mode (math payloads only)
attack_script ssti_tester "https://TARGET/render" --param template --quick

Phase 2: Generic Detection Payloads

Inject into every user-controlled parameter:

{{7*7}}           → 49 (Jinja2, Twig)
${7*7}            → 49 (FreeMarker, Velocity, EL)
<%= 7*7 %>        → 49 (ERB, JSP)
#{7*7}            → 49 (Thymeleaf)
{{7*'7'}}         → 7777777 (Jinja2 string multiplication)

Phase 3: Engine Fingerprinting

This is the opening of the README. Read the full README on GitHub.

Frequently asked about Server-Side Template Injection

What else does CyberStrikeus publish alongside Server-Side Template Injection?
Server-Side Template Injection is one of 51 skills that DirSkills catalogs from CyberStrikeus/CyberStrike, the repository it ships in. Its siblings there include AMI Age Compliance, AMI Encryption Check and AMI Naming Convention Compliance. Each one is a separate skill with its own page in this directory, installs the same way Server-Side Template Injection does, and is maintained by CyberStrikeus in that same repository. The rest of the collection is listed on the CyberStrikeus/CyberStrike page.
How does Server-Side Template Injection compare to other Quality skills?
Server-Side Template Injection ranks #608 by stars among the 1354 Quality skills in this catalog. The most-starred ones next to it are Benchmark, Benchmark Optimization Loop and API Design Patterns. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Server-Side Template Injection against them. Open each page to compare what they document and how they install.