pi-lens/rules/tree-sitter-queries/python/python-sql-injection.yml

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# Python Security
# Detects dynamic SQL passed into execute-like APIs.
id: python-sql-injection
name: SQL Injection Risk
severity: error
category: security
defect_class: injection
inline_tier: blocking
language: python

message: "Potential SQL injection sink — use parameterized queries"

description: |
  Dynamic SQL strings passed to execute-style APIs can enable SQL injection.
  Catches:
  - cursor.execute("SELECT " + var) — string concatenation (always unsafe)
  - cursor.execute(dynamic_sql) — variable with NO params arg (could be unsafe)
  
  Suppressed:
  - cursor.execute(query, params) — parameterized query (safe)
  - session.execute(...) — receiver conventionally named for a SQLAlchemy session
  - x.execute(select(...)) — statement builder in argument position (safe by
    construction)
  - db.query(...) / db.execute(stmt) where `db: Session` and `Session` is proven
    from a same-file `sqlalchemy.orm` / `sqlalchemy.ext.asyncio` import, and
    `stmt` is bound exactly once to a builder call
  - cursor.execute(sql.SQL("...").format(sql.Identifier(...))) where `sql` is
    an unshadowed same-file psycopg or psycopg2 import and every format argument
    is an Identifier

  Other raw, dynamic, or ambiguous SQL remains diagnostic so this rule fails
  closed when it cannot prove the safe API provenance.
  
  ✅ FIX: use placeholders and parameter binding instead of string composition.

query: |
  (call
    function: (attribute
      object: (_) @OBJ
      attribute: (identifier) @FN)
    arguments: (argument_list
      [(binary_operator) (identifier) (call)] @SQL
      (_)*) @ARGS)

metavars:
  - OBJ
  - FN
  - SQL
  - ARGS

post_filter: py_sql_injection_sink

has_fix: false

tags:
  - python
  - security
  - sql-injection
  - cwe-89
  - owasp-a03

examples:
  bad: |
    cursor.execute("SELECT * FROM users WHERE id = " + user_id)
  
  good: |
    cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))