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Merge pull request #5463 from jorgectf/jorgectf/python/headerInjection
Python: Add Header Injection query
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‎python/ql/src/experimental/Security/CWE-113/HeaderInjection.qhelp

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<!DOCTYPE qhelp PUBLIC
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"-//Semmle//qhelp//EN"
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"qhelp.dtd">
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<qhelp>
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<overview>
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<p>If an HTTP Header is built using string concatenation or string formatting, and the
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components of the concatenation include user input, a user
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is likely to be able to manipulate the response.</p>
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</overview>
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<recommendation>
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<p>User input should not be included in an HTTP Header.</p>
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</recommendation>
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<example>
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<p>In the following example, the code appends a user-provided value into a header.</p>
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<sample src="header_injection.py" />
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</example>
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<references>
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<li>OWASP: <a href="https://owasp.org/www-community/attacks/HTTP_Response_Splitting">HTTP Response Splitting</a>.</li>
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<li>Python Security: <a href="https://python-security.readthedocs.io/vuln/http-header-injection.html">HTTP header injection</a>.</li>
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<li>SonarSource: <a href="https://rules.sonarsource.com/python/RSPEC-5167">RSPEC-5167</a>.</li>
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</references>
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</qhelp>

‎python/ql/src/experimental/Security/CWE-113/HeaderInjection.ql

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/**
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* @name HTTP Header Injection
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* @description User input should not be used in HTTP headers, otherwise a malicious user
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* may be able to inject a value that could manipulate the response.
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* @kind path-problem
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* @problem.severity error
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* @id py/header-injection
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* @tags security
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* external/cwe/cwe-113
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* external/cwe/cwe-079
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*/
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// determine precision above
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import python
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import experimental.semmle.python.security.injection.HTTPHeaders
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import DataFlow::PathGraph
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from HeaderInjectionFlowConfig config, DataFlow::PathNode source, DataFlow::PathNode sink
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where config.hasFlowPath(source, sink)
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select sink.getNode(), source, sink, "$@ HTTP header is constructed from a $@.", sink.getNode(),
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"This", source.getNode(), "user-provided value"

‎python/ql/src/experimental/Security/CWE-113/header_injection.py

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from flask import Response, request, Flask, make_response
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@app.route("/flask_Response")
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def flask_Response():
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rfs_header = request.args["rfs_header"]
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response = Response()
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response.headers['HeaderName'] = rfs_header
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return response

‎python/ql/src/experimental/semmle/python/Concepts.qll

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@@ -253,3 +253,46 @@ class NoSQLSanitizer extends DataFlow::Node {
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/** Gets the argument that specifies the NoSQL query to be sanitized. */
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DataFlow::Node getAnInput() { result = range.getAnInput() }
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}
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/** Provides classes for modeling HTTP Header APIs. */
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module HeaderDeclaration {
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/**
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* A data-flow node that collects functions setting HTTP Headers.
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*
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* Extend this class to model new APIs. If you want to refine existing API models,
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* extend `HeaderDeclaration` instead.
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*/
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abstract class Range extends DataFlow::Node {
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/**
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* Gets the argument containing the header name.
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*/
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abstract DataFlow::Node getNameArg();
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/**
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* Gets the argument containing the header value.
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*/
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abstract DataFlow::Node getValueArg();
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}
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}
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/**
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* A data-flow node that collects functions setting HTTP Headers.
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*
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* Extend this class to refine existing API models. If you want to model new APIs,
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* extend `HeaderDeclaration::Range` instead.
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*/
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class HeaderDeclaration extends DataFlow::Node {
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HeaderDeclaration::Range range;
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HeaderDeclaration() { this = range }
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/**
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* Gets the argument containing the header name.
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*/
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DataFlow::Node getNameArg() { result = range.getNameArg() }
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/**
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* Gets the argument containing the header value.
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*/
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DataFlow::Node getValueArg() { result = range.getValueArg() }
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}

‎python/ql/src/experimental/semmle/python/Frameworks.qll

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*/
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private import experimental.semmle.python.frameworks.Stdlib
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private import experimental.semmle.python.frameworks.Flask
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private import experimental.semmle.python.frameworks.Django
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private import experimental.semmle.python.frameworks.Werkzeug
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private import experimental.semmle.python.frameworks.LDAP
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private import experimental.semmle.python.frameworks.NoSQL
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private import experimental.semmle.python.frameworks.Log

‎python/ql/src/experimental/semmle/python/frameworks/Django.qll

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/**
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* Provides classes modeling security-relevant aspects of the `django` PyPI package.
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* See https://www.djangoproject.com/.
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*/
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private import python
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private import semmle.python.frameworks.Django
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private import semmle.python.dataflow.new.DataFlow
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private import experimental.semmle.python.Concepts
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private import semmle.python.ApiGraphs
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import semmle.python.dataflow.new.RemoteFlowSources
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private module PrivateDjango {
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private module django {
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API::Node http() { result = API::moduleImport("django").getMember("http") }
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module http {
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API::Node response() { result = http().getMember("response") }
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API::Node request() { result = http().getMember("request") }
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module request {
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module HttpRequest {
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class DjangoGETParameter extends DataFlow::Node, RemoteFlowSource::Range {
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DjangoGETParameter() { this = request().getMember("GET").getMember("get").getACall() }
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override string getSourceType() { result = "django.http.request.GET.get" }
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}
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}
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}
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module response {
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module HttpResponse {
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API::Node baseClassRef() {
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result = response().getMember("HttpResponse").getReturn()
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or
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// Handle `django.http.HttpResponse` alias
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result = http().getMember("HttpResponse").getReturn()
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}
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/** Gets a reference to a header instance. */
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private DataFlow::LocalSourceNode headerInstance(DataFlow::TypeTracker t) {
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t.start() and
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(
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exists(SubscriptNode subscript |
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subscript.getObject() = baseClassRef().getAUse().asCfgNode() and
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result.asCfgNode() = subscript
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)
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or
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result.(DataFlow::AttrRead).getObject() = baseClassRef().getAUse()
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)
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or
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exists(DataFlow::TypeTracker t2 | result = headerInstance(t2).track(t2, t))
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}
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/** Gets a reference to a header instance use. */
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private DataFlow::Node headerInstance() {
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headerInstance(DataFlow::TypeTracker::end()).flowsTo(result)
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}
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/** Gets a reference to a header instance call with `__setitem__`. */
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private DataFlow::Node headerSetItemCall() {
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result = headerInstance() and
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result.(DataFlow::AttrRead).getAttributeName() = "__setitem__"
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}
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class DjangoResponseSetItemCall extends DataFlow::CallCfgNode, HeaderDeclaration::Range {
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DjangoResponseSetItemCall() { this.getFunction() = headerSetItemCall() }
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override DataFlow::Node getNameArg() { result = this.getArg(0) }
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override DataFlow::Node getValueArg() { result = this.getArg(1) }
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}
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class DjangoResponseDefinition extends DataFlow::Node, HeaderDeclaration::Range {
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DataFlow::Node headerInput;
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DjangoResponseDefinition() {
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this.asCfgNode().(DefinitionNode) = headerInstance().asCfgNode() and
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headerInput.asCfgNode() = this.asCfgNode().(DefinitionNode).getValue()
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}
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override DataFlow::Node getNameArg() {
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result.asExpr() = this.asExpr().(Subscript).getIndex()
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}
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override DataFlow::Node getValueArg() { result = headerInput }
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}
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}
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}
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}
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}
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}

‎python/ql/src/experimental/semmle/python/frameworks/Flask.qll

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/**
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* Provides classes modeling security-relevant aspects of the `flask` PyPI package.
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* See https://flask.palletsprojects.com/en/1.1.x/.
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*/
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private import python
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private import semmle.python.frameworks.Flask
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private import semmle.python.dataflow.new.DataFlow
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private import experimental.semmle.python.Concepts
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private import semmle.python.ApiGraphs
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module ExperimentalFlask {
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/**
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* A reference to either `flask.make_response` function, or the `make_response` method on
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* an instance of `flask.Flask`. This creates an instance of the `flask_response`
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* class (class-attribute on a flask application), which by default is
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* `flask.Response`.
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*
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* See
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* - https://flask.palletsprojects.com/en/1.1.x/api/#flask.Flask.make_response
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* - https://flask.palletsprojects.com/en/1.1.x/api/#flask.make_response
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*/
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private API::Node flaskMakeResponse() {
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result =
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[API::moduleImport("flask"), Flask::FlaskApp::instance()]
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.getMember(["make_response", "jsonify", "make_default_options_response"])
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}
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/** Gets a reference to a header instance. */
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private DataFlow::LocalSourceNode headerInstance(DataFlow::TypeTracker t) {
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t.start() and
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result.(DataFlow::AttrRead).getObject().getALocalSource() =
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[Flask::Response::classRef(), flaskMakeResponse()].getReturn().getAUse()
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or
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exists(DataFlow::TypeTracker t2 | result = headerInstance(t2).track(t2, t))
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}
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/** Gets a reference to a header instance use. */
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private DataFlow::Node headerInstance() {
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headerInstance(DataFlow::TypeTracker::end()).flowsTo(result)
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}
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/** Gets a reference to a header instance call/subscript */
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private DataFlow::Node headerInstanceCall() {
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headerInstance() in [result.(DataFlow::AttrRead), result.(DataFlow::AttrRead).getObject()] or
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headerInstance().asExpr() = result.asExpr().(Subscript).getObject()
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}
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class FlaskHeaderDefinition extends DataFlow::Node, HeaderDeclaration::Range {
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DataFlow::Node headerInput;
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FlaskHeaderDefinition() {
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this.asCfgNode().(DefinitionNode) = headerInstanceCall().asCfgNode() and
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headerInput.asCfgNode() = this.asCfgNode().(DefinitionNode).getValue()
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}
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override DataFlow::Node getNameArg() { result.asExpr() = this.asExpr().(Subscript).getIndex() }
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override DataFlow::Node getValueArg() { result = headerInput }
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}
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private class FlaskMakeResponseExtend extends DataFlow::CallCfgNode, HeaderDeclaration::Range {
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KeyValuePair item;
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FlaskMakeResponseExtend() {
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this.getFunction() = headerInstanceCall() and
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item = this.getArg(_).asExpr().(Dict).getAnItem()
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}
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override DataFlow::Node getNameArg() { result.asExpr() = item.getKey() }
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override DataFlow::Node getValueArg() { result.asExpr() = item.getValue() }
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}
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private class FlaskResponse extends DataFlow::CallCfgNode, HeaderDeclaration::Range {
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KeyValuePair item;
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FlaskResponse() { this = Flask::Response::classRef().getACall() }
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override DataFlow::Node getNameArg() { result.asExpr() = item.getKey() }
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override DataFlow::Node getValueArg() { result.asExpr() = item.getValue() }
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}
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}

‎python/ql/src/experimental/semmle/python/frameworks/Werkzeug.qll

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/**
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* Provides classes modeling security-relevant aspects of the `Werkzeug` PyPI package.
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* See
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* - https://pypi.org/project/Werkzeug/
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* - https://werkzeug.palletsprojects.com/en/1.0.x/#werkzeug
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*/
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private import python
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private import semmle.python.frameworks.Flask
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private import semmle.python.dataflow.new.DataFlow
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private import experimental.semmle.python.Concepts
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private import semmle.python.ApiGraphs
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private module Werkzeug {
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module datastructures {
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module Headers {
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class WerkzeugHeaderAddCall extends DataFlow::CallCfgNode, HeaderDeclaration::Range {
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WerkzeugHeaderAddCall() {
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this.getFunction().(DataFlow::AttrRead).getObject().getALocalSource() =
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API::moduleImport("werkzeug")
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.getMember("datastructures")
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.getMember("Headers")
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.getACall() and
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this.getFunction().(DataFlow::AttrRead).getAttributeName() = "add"
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}
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override DataFlow::Node getNameArg() { result = this.getArg(0) }
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override DataFlow::Node getValueArg() { result = this.getArg(1) }
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}
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}
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}
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}

‎python/ql/src/experimental/semmle/python/security/injection/HTTPHeaders.qll

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import python
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import experimental.semmle.python.Concepts
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import semmle.python.dataflow.new.DataFlow
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import semmle.python.dataflow.new.TaintTracking
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import semmle.python.dataflow.new.RemoteFlowSources
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/**
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* A taint-tracking configuration for detecting HTTP Header injections.
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*/
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class HeaderInjectionFlowConfig extends TaintTracking::Configuration {
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HeaderInjectionFlowConfig() { this = "HeaderInjectionFlowConfig" }
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override predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
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override predicate isSink(DataFlow::Node sink) {
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exists(HeaderDeclaration headerDeclaration |
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sink in [headerDeclaration.getNameArg(), headerDeclaration.getValueArg()]
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)
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}
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}

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