Python: Some renaming of flow states

This commit is contained in:
Rasmus Lerchedahl Petersen
2023-09-28 14:24:49 +02:00
parent d5b64c5ff2
commit 3043633d9c
2 changed files with 42 additions and 28 deletions

View File

@@ -17,7 +17,7 @@ import semmle.python.Concepts
module NoSqlInjection {
private newtype TFlowState =
TStringInput() or
TDictInput()
TInterpretedStringInput()
/** A flow state, tracking the structure of the input. */
abstract class FlowState extends TFlowState {
@@ -30,29 +30,33 @@ module NoSqlInjection {
override string toString() { result = "StringInput" }
}
/** A state where input is a dictionary. */
class DictInput extends FlowState, TDictInput {
override string toString() { result = "DictInput" }
/**
* A state where input is a string that has been interpreted.
* For instance, it could have been turned into a dictionary,
* or evaluated as javascript code.
*/
class InterpretedStringInput extends FlowState, TInterpretedStringInput {
override string toString() { result = "InterpretedStringInput" }
}
/** A source allowing string inputs. */
abstract class StringSource extends DataFlow::Node { }
/** A source allowing dictionary inputs. */
abstract class DictSource extends DataFlow::Node { }
/** A source of interpreted strings. */
abstract class InterpretedStringSource extends DataFlow::Node { }
/** A sink vulnerable to user controlled strings. */
abstract class StringSink extends DataFlow::Node { }
/** A sink vulnerable to user controlled dictionaries. */
abstract class DictSink extends DataFlow::Node { }
/** A sink vulnerable to user controlled interpreted strings. */
abstract class InterpretedStringSink extends DataFlow::Node { }
/** A data flow node where a string is converted into a dictionary. */
abstract class StringToDictConversion extends DataFlow::Node {
/** Gets the argument that specifies the string to be converted. */
/** A data flow node where a string is being interpreted. */
abstract class StringInterpretation extends DataFlow::Node {
/** Gets the argument that specifies the string to be interpreted. */
abstract DataFlow::Node getAnInput();
/** Gets the resulting dictionary. */
/** Gets the result of interpreting the string. */
abstract DataFlow::Node getOutput();
}
@@ -68,14 +72,23 @@ module NoSqlInjection {
}
}
/** A NoSQL query that is vulnerable to user controlled dictionaries. */
class NoSqlExecutionAsDictSink extends DictSink {
NoSqlExecutionAsDictSink() { this = any(NoSqlExecution noSqlExecution).getQuery() }
/** A NoSQL query that is vulnerable to user controlled InterpretedStringionaries. */
class NoSqlExecutionAsInterpretedStringSink extends InterpretedStringSink {
NoSqlExecutionAsInterpretedStringSink() { this = any(NoSqlExecution noSqlExecution).getQuery() }
}
/** A JSON decoding converts a string to a dictionary. */
class JsonDecoding extends Decoding, StringToDictConversion {
JsonDecoding() { this.getFormat() in ["JSON", "NoSQL"] }
/** A JSON decoding converts a string to a Dictionary. */
class JsonDecoding extends Decoding, StringInterpretation {
JsonDecoding() { this.getFormat() = "JSON" }
override DataFlow::Node getAnInput() { result = Decoding.super.getAnInput() }
override DataFlow::Node getOutput() { result = Decoding.super.getOutput() }
}
/** A NoSQL decoding interprets a string. */
class NoSqlDecoding extends Decoding, StringInterpretation {
NoSqlDecoding() { this.getFormat() = "NoSQL" }
override DataFlow::Node getAnInput() { result = Decoding.super.getAnInput() }

View File

@@ -18,8 +18,8 @@ module NoSqlInjectionConfig implements DataFlow::StateConfigSig {
source instanceof C::StringSource and
state instanceof C::StringInput
or
source instanceof C::DictSource and
state instanceof C::DictInput
source instanceof C::InterpretedStringSource and
state instanceof C::InterpretedStringInput
}
predicate isSink(DataFlow::Node sink, FlowState state) {
@@ -27,29 +27,30 @@ module NoSqlInjectionConfig implements DataFlow::StateConfigSig {
(
state instanceof C::StringInput
or
// since dictionaries can encode strings
state instanceof C::DictInput
// since InterpretedStrings can include strings,
// e.g. JSON objects can encode strings.
state instanceof C::InterpretedStringInput
)
or
sink instanceof C::DictSink and
state instanceof C::DictInput
sink instanceof C::InterpretedStringSink and
state instanceof C::InterpretedStringInput
}
predicate isBarrier(DataFlow::Node node, FlowState state) {
// Block `StringInput` paths here, since they change state to `DictInput`
exists(C::StringToDictConversion c | node = c.getOutput()) and
// Block `StringInput` paths here, since they change state to `InterpretedStringInput`
exists(C::StringInterpretation c | node = c.getOutput()) and
state instanceof C::StringInput
}
predicate isAdditionalFlowStep(
DataFlow::Node nodeFrom, FlowState stateFrom, DataFlow::Node nodeTo, FlowState stateTo
) {
exists(C::StringToDictConversion c |
exists(C::StringInterpretation c |
nodeFrom = c.getAnInput() and
nodeTo = c.getOutput()
) and
stateFrom instanceof C::StringInput and
stateTo instanceof C::DictInput
stateTo instanceof C::InterpretedStringInput
}
predicate isBarrier(DataFlow::Node node) {