Python: use SqlConstruction in SqlAlchemy and

`SqlInjection`
This commit is contained in:
Rasmus Lerchedahl Petersen
2021-10-25 13:30:14 +02:00
parent e5b68d68cb
commit 5a02b3880e
6 changed files with 26 additions and 24 deletions

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@@ -313,9 +313,11 @@ module SqlAlchemy {
* A construction of a `sqlalchemy.sql.expression.TextClause`, which represents a
* textual SQL string directly.
*/
abstract class TextClauseConstruction extends DataFlow::CallCfgNode {
abstract class TextClauseConstruction extends SqlConstruction::Range, DataFlow::CallCfgNode {
/** Gets the argument that specifies the SQL text. */
DataFlow::Node getTextArg() { result in [this.getArg(0), this.getArgByName("text")] }
final override DataFlow::Node getSql() {
result in [this.getArg(0), this.getArgByName("text")]
}
}
/** `TextClause` constructions from the `sqlalchemy` package. */

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@@ -42,6 +42,13 @@ module SqlInjection {
*/
class RemoteFlowSourceAsSource extends Source, RemoteFlowSource { }
/**
* A SQL statement of a SQL construction, considered as a flow sink.
*/
class SqlConstructionAsSink extends Sink {
SqlConstructionAsSink() { this = any(SqlConstruction c).getSql() }
}
/**
* A SQL statement of a SQL execution, considered as a flow sink.
*/
@@ -49,13 +56,6 @@ module SqlInjection {
SqlExecutionAsSink() { this = any(SqlExecution e).getSql() }
}
/**
* The text argument of a SQLAlchemy TextClause construction, considered as a flow sink.
*/
class TextArgAsSink extends Sink {
TextArgAsSink() { this = any(SqlAlchemy::TextClause::TextClauseConstruction tcc).getTextArg() }
}
/**
* A comparison with a constant string, considered as a sanitizer-guard.
*/

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@@ -12,7 +12,7 @@ db = SQLAlchemy(app)
# - https://github.com/pallets/flask-sqlalchemy/blob/931ec00d1e27f51508e05706eef41cc4419a0b32/src/flask_sqlalchemy/__init__.py#L765
# - https://github.com/pallets/flask-sqlalchemy/blob/931ec00d1e27f51508e05706eef41cc4419a0b32/src/flask_sqlalchemy/__init__.py#L99-L109
assert str(type(db.text("Foo"))) == "<class 'sqlalchemy.sql.elements.TextClause'>"
assert str(type(db.text("Foo"))) == "<class 'sqlalchemy.sql.elements.TextClause'>" # $ constructedSql="Foo"
# also has engine/session instantiated
@@ -44,8 +44,8 @@ assert result.fetchall() == [("Foo",)]
# text
t = db.text("foo")
t = db.text("foo") # $ constructedSql="foo"
assert isinstance(t, sqlalchemy.sql.expression.TextClause)
t = db.text(text="foo")
t = db.text(text="foo") # $ constructedSql="foo"
assert isinstance(t, sqlalchemy.sql.expression.TextClause)

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@@ -46,7 +46,7 @@ with engine.begin() as connection:
connection.execute("some sql") # $ getSql="some sql"
# Injection requiring the text() taint-step
t = text("some sql")
t = text("some sql") # $ constructedSql="some sql"
session.query(User).filter(t)
session.query(User).group_by(User.id).having(t)
session.query(User).group_by(t).first()

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@@ -6,7 +6,7 @@ import sqlalchemy.orm
# either v1.4 or v2.0, such that we cover both.
raw_sql = "select 'FOO'"
text_sql = sqlalchemy.text(raw_sql)
text_sql = sqlalchemy.text(raw_sql) # $ constructedSql=raw_sql
Base = sqlalchemy.orm.declarative_base()
@@ -169,7 +169,7 @@ assert session.query(For14).all()[0].id == 14
# and now we can do the actual querying
text_foo = sqlalchemy.text("'FOO'")
text_foo = sqlalchemy.text("'FOO'") # $ constructedSql="'FOO'"
# filter_by is only vulnerable to injection if sqlalchemy.text is used, which is evident
# from the logs produced if this file is run
@@ -298,7 +298,7 @@ with engine.connect() as conn:
assert scalar_result == "FOO"
# This is a contrived example
select = sqlalchemy.select(sqlalchemy.text("'BAR'"))
select = sqlalchemy.select(sqlalchemy.text("'BAR'")) # $ constructedSql="'BAR'"
result = conn.execute(select) # $ getSql=select
assert result.fetchall() == [("BAR",)]

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@@ -8,14 +8,14 @@ def test_taint():
ensure_tainted(ts) # $ tainted
t1 = sqlalchemy.text(ts)
t2 = sqlalchemy.text(text=ts)
t3 = sqlalchemy.sql.text(ts)
t4 = sqlalchemy.sql.text(text=ts)
t5 = sqlalchemy.sql.expression.text(ts)
t6 = sqlalchemy.sql.expression.text(text=ts)
t7 = sqlalchemy.sql.expression.TextClause(ts)
t8 = sqlalchemy.sql.expression.TextClause(text=ts)
t1 = sqlalchemy.text(ts) # $ constructedSql=ts
t2 = sqlalchemy.text(text=ts) # $ constructedSql=ts
t3 = sqlalchemy.sql.text(ts) # $ constructedSql=ts
t4 = sqlalchemy.sql.text(text=ts) # $ constructedSql=ts
t5 = sqlalchemy.sql.expression.text(ts) # $ constructedSql=ts
t6 = sqlalchemy.sql.expression.text(text=ts) # $ constructedSql=ts
t7 = sqlalchemy.sql.expression.TextClause(ts) # $ constructedSql=ts
t8 = sqlalchemy.sql.expression.TextClause(text=ts) # $ constructedSql=ts
# Since we flag user-input to a TextClause with its' own query, we don't want to
# have a taint-step for it as that would lead to us also giving an alert for normal