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pentest-whitebox-code-review

Testing & Quality
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Source code security audit using backward taint analysis, slot type classification, render context verification, and 3-phase parallel review producing an exploitation queue.

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Source SKILL.md: https://github.com/jd-opensource/JoySafeter/blob/HEAD/skills/pentest-whitebox-code-review/SKILL.md

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Pentest Whitebox Code Review

Purpose

Perform systematic white-box source code security audit using Shannon's backward taint analysis methodology. Traces from dangerous sinks back to user-controlled sources, classifies injection contexts by slot type, verifies XSS render contexts, and produces a prioritized exploitation queue for downstream proof-driven exploitation.

Prerequisites

Authorization Requirements

  • Written authorization with explicit scope for source code review
  • Source code access — full repository with version control history
  • Architecture documentation if available (data flow diagrams, API specs)
  • Deployment configuration access (environment variables, secrets management)

Environment Setup

  • semgrep with custom rules for taint analysis
  • CodeQL database built for target language
  • ripgrep for fast pattern searching
  • jadx for Android APK decompilation (if applicable)
  • Source map extraction tools for minified JavaScript
  • AST parsing tools for target language (tree-sitter, babel, etc.)

Core Workflow

Phase 1: Discovery

  1. Architecture Mapping: Identify application layers (routing, controllers, services, data access, templates). Map data flow from HTTP entry points through business logic to database/file/external sinks.
  2. Entry Point Enumeration: Catalog all user-controlled input sources — HTTP parameters, headers, cookies, file uploads, WebSocket messages, environment variables, database reads of user-stored data.
  3. Security Pattern Inventory: Identify existing security controls — input validation functions, output encoding helpers, parameterized query patterns, CSRF protections, authentication middleware, rate limiters.

Phase 2: Vulnerability Analysis (5 Parallel Tracks)

  1. Injection Sink Hunting: Backward taint from SQL/command/file/template sinks to sources. Classify each sink by slot type: SQL-val, SQL-ident, CMD-argument, FILE-path, TEMPLATE-expr. Verify whether parameterization or sanitization breaks the taint chain.
  2. XSS Render Context Analysis: Identify all dynamic output points in templates/responses. Classify each by render context: HTML_BODY, HTML_ATTRIBUTE, JAVASCRIPT_STRING, URL_PARAM, CSS_VALUE. Verify context-appropriate encoding is applied at each output point.
  3. Authentication Checklist (9-point): Transport security, rate limiting, session management, token properties, session fixation resistance, password policy enforcement, login response uniformity, account recovery security, SSO/OAuth implementation.
  4. Authorization Model Review (3-type): Horizontal (same-role cross-user access), vertical (privilege escalation across roles), context-workflow (state-dependent authorization bypass).
  5. SSRF Sink Hunting: Identify all outbound request sinks. Classify by type: classic (direct URL), blind (no response), semi-blind (partial response), stored (deferred execution). Trace URL construction from user input to request dispatch.

Phase 3: Synthesis

  1. Confidence Scoring & Exploitation Queue: Score each finding by taint chain completeness, sanitization bypass likelihood, and impact severity. Generate exploitation queue JSON for downstream exploit validation.

Slot Type Classification

Slot TypeSink PatternSanitization Required
SQL-valQuery parameter value positionParameterized query / prepared statement
SQL-identTable name, column name, ORDER BYAllowlist validation
CMD-argumentShell command argumentArgument escaping + allowlist
FILE-pathFile read/write path constructionPath canonicalization + allowlist
TEMPLATE-exprTemplate engine expressionContext-aware auto-escaping

Render Context Classification

ContextOutput LocationEncoding Required
HTML_BODYBetween HTML tagsHTML entity encoding
HTML_ATTRIBUTEInside attribute valuesAttribute encoding + quoting
JAVASCRIPT_STRINGInside JS string literalsJavaScript Unicode escaping
URL_PARAMURL query parameter valuesURL percent encoding
CSS_VALUEInside CSS property valuesCSS hex encoding

Tool Categories

CategoryToolsPurpose
Taint Analysissemgrep, CodeQLAutomated sink-to-source taint tracing
Pattern Searchripgrep, ast-grepFast code pattern matching
Decompilationjadx, sourcemap-extractRecover source from compiled artifacts
AST Parsingtree-sitter, babelLanguage-aware code structure analysis
Dependency Auditnpm audit, pip-audit, snykKnown vulnerability detection

References

  • references/tools.md - Tool function signatures and parameters
  • references/workflows.md - Taint analysis workflows and vulnerability patterns