Name: sast-ssti
Rating: 68 (1 reviews)
Author: utkusen

sast-ssti

Detect Server-Side Template Injection (SSTI) vulnerabilities in a codebase using a three-phase approach: recon (find template rendering sites that use dynamic strings), batched verify (trace user input to those sites in parallel subagents, 3 candidates each), and merge (consolidate batch results). Requires sast/architecture.md (run sast-analysis first). Outputs findings to sast/ssti-results.md. Use when asked to find SSTI or template injection bugs.

Quality

82%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

The canonical home for this skill is sast-ssti in utkusen/sast-skills

Quality

Content

77%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A highly actionable, well-sequenced detection skill with explicit validation checkpoints and checklists, but it is verbose in places and inlines a large pattern/example catalog that belongs in separate bundled reference files.

Suggestions

Trim or remove the 'What is SSTI' conceptual section — Claude already knows SSTI — and keep only the template-string-vs-context distinction that drives detection.

De-duplicate the engine call patterns: list them once in a referenced patterns file (e.g. references/patterns.md) and have Phase 1 point to it, instead of maintaining two parallel lists in the body.

Move the per-language vulnerable/secure examples into a references/examples.md and inline only the project's matched stack, which the skill already does for Phase 2 subagents.

Dimension	Reasoning	Score
Conciseness	The 'What is SSTI' section explains a concept Claude already knows, and the template-engine call patterns are listed twice — once under 'What SSTI IS' and again as Phase 1's 19 numbered search patterns — so the body could be meaningfully tightened.	3 / 5
Actionability	Subagent prompts are copy-paste-ready with exact output formats, concrete per-language grep patterns, a precise batching procedure (3 candidates per subagent), and engine-appropriate payload examples covering the common cases.	5 / 5
Workflow Clarity	Three phases are explicitly sequenced with an embedded validation gate ('After Phase 1: Check for Candidates Before Proceeding' skips Phase 2/3 on zero results), cross-phase dependency notes, and an 'Important Reminders' checklist.	5 / 5
Progressive Disclosure	No bundle files exist, yet the body inlines large reference-style material (a 19-language pattern catalog and vulnerable/secure examples across 10 languages) that would be better split into separate reference files with clearly signaled navigation.	3 / 5
	Total	16 / 20 Passed

Description

87%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong, specific description that names a clear niche, lists concrete three-phase actions, and provides an explicit 'Use when' trigger. Minor additional synonyms would push trigger quality and specificity to full marks.

Dimension	Reasoning	Score
Specificity	Lists several concrete actions — 'recon (find template rendering sites that use dynamic strings), batched verify (trace user input to those sites in parallel subagents, 3 candidates each), and merge (consolidate batch results)' — but stops short of the comprehensive multi-action coverage of a 5.	4 / 5
Completeness	Clearly states what it does ('Detect Server-Side Template Injection... using a three-phase approach') and explicitly when to use it ('Use when asked to find SSTI or template injection bugs'), satisfying both halves with a concrete trigger phrase.	5 / 5
Trigger Term Quality	'Use when asked to find SSTI or template injection bugs' gives good natural-term coverage with synonyms (SSTI, template injection), though a few related phrasings users might say are absent.	4 / 5
Distinctiveness Conflict Risk	Occupies a clear niche (SSTI detection) with distinct triggers ('find SSTI or template injection bugs'), making conflict with other skills unlikely.	5 / 5
	Total	18 / 20 Passed

Validation

93%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
skill_md_line_count	SKILL.md is long (607 lines); consider splitting into references/ and linking	Warning

	Total	15 / 16 Passed

Repository: utkusen/sast-skills
Path: sast-files/.claude/skills/sast-ssti/SKILL.md
Commit: db52227

Reviewed: 1 hour ago

Table of Contents

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