Python: Move experimental ReflectedXSS to new dataflow API

Author: RasmusWL

python/ql/src/experimental/Security/CWE-079/ReflectedXSS.ql

@@ -16,9 +16,9 @@
 // determine precision above
 import python
 import experimental.semmle.python.security.dataflow.ReflectedXSS
-import DataFlow::PathGraph
+import ReflectedXSSFlow::PathGraph
 
-from ReflectedXssConfiguration config, DataFlow::PathNode source, DataFlow::PathNode sink
-where config.hasFlowPath(source, sink)
+from ReflectedXSSFlow::PathNode source, ReflectedXSSFlow::PathNode sink
+where ReflectedXSSFlow::flowPath(source, sink)
 select sink.getNode(), source, sink, "Cross-site scripting vulnerability due to $@.",
   source.getNode(), "a user-provided value"

python/ql/src/experimental/semmle/python/security/dataflow/ReflectedXSS.qll

@@ -16,20 +16,18 @@ import semmle.python.ApiGraphs
  * A taint-tracking configuration for detecting reflected server-side cross-site
  * scripting vulnerabilities.
  */
-class ReflectedXssConfiguration extends TaintTracking::Configuration {
-  ReflectedXssConfiguration() { this = "ReflectedXssConfiguration" }
+private module ReflectedXSSConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
 
-  override predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
+  predicate isSink(DataFlow::Node sink) { sink = any(EmailSender email).getHtmlBody() }
 
-  override predicate isSink(DataFlow::Node sink) { sink = any(EmailSender email).getHtmlBody() }
-
-  override predicate isSanitizer(DataFlow::Node sanitizer) {
+  predicate isBarrier(DataFlow::Node sanitizer) {
     sanitizer = any(HtmlEscaping esc).getOutput()
     or
     sanitizer instanceof StringConstCompareBarrier
   }
 
-  override predicate isAdditionalTaintStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
+  predicate isAdditionalFlowStep(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
     exists(DataFlow::CallCfgNode htmlContentCall |
       htmlContentCall =
         API::moduleImport("sendgrid")
@@ -42,3 +40,6 @@ class ReflectedXssConfiguration extends TaintTracking::Configuration {
     )
   }
 }
+
+/** Global taint-tracking for detecting "TODO" vulnerabilities. */
+module ReflectedXSSFlow = TaintTracking::Global<ReflectedXSSConfig>;

python/ql/test/experimental/query-tests/Security/CWE-079/ReflectedXSS.expected

@@ -12,7 +12,8 @@ edges
 | sendgrid_mail.py:1:19:1:25 | GSSA Variable request | sendgrid_mail.py:26:34:26:40 | ControlFlowNode for request |
 | sendgrid_mail.py:1:19:1:25 | GSSA Variable request | sendgrid_mail.py:37:41:37:47 | ControlFlowNode for request |
 | sendgrid_mail.py:14:22:14:28 | ControlFlowNode for request | sendgrid_mail.py:14:22:14:49 | ControlFlowNode for Subscript |
-| sendgrid_mail.py:26:34:26:40 | ControlFlowNode for request | sendgrid_mail.py:26:22:26:62 | ControlFlowNode for HtmlContent() |
+| sendgrid_mail.py:26:34:26:40 | ControlFlowNode for request | sendgrid_mail.py:26:34:26:61 | ControlFlowNode for Subscript |
+| sendgrid_mail.py:26:34:26:61 | ControlFlowNode for Subscript | sendgrid_mail.py:26:22:26:62 | ControlFlowNode for HtmlContent() |
 | sendgrid_mail.py:37:41:37:47 | ControlFlowNode for request | sendgrid_mail.py:37:41:37:68 | ControlFlowNode for Subscript |
 | sendgrid_via_mail_send_post_request_body_bad.py:3:19:3:25 | ControlFlowNode for ImportMember | sendgrid_via_mail_send_post_request_body_bad.py:3:19:3:25 | GSSA Variable request |
 | sendgrid_via_mail_send_post_request_body_bad.py:3:19:3:25 | GSSA Variable request | sendgrid_via_mail_send_post_request_body_bad.py:16:51:16:57 | ControlFlowNode for request |
@@ -52,6 +53,7 @@ nodes
 | sendgrid_mail.py:14:22:14:49 | ControlFlowNode for Subscript | semmle.label | ControlFlowNode for Subscript |
 | sendgrid_mail.py:26:22:26:62 | ControlFlowNode for HtmlContent() | semmle.label | ControlFlowNode for HtmlContent() |
 | sendgrid_mail.py:26:34:26:40 | ControlFlowNode for request | semmle.label | ControlFlowNode for request |
+| sendgrid_mail.py:26:34:26:61 | ControlFlowNode for Subscript | semmle.label | ControlFlowNode for Subscript |
 | sendgrid_mail.py:37:41:37:47 | ControlFlowNode for request | semmle.label | ControlFlowNode for request |
 | sendgrid_mail.py:37:41:37:68 | ControlFlowNode for Subscript | semmle.label | ControlFlowNode for Subscript |
 | sendgrid_via_mail_send_post_request_body_bad.py:3:19:3:25 | ControlFlowNode for ImportMember | semmle.label | ControlFlowNode for ImportMember |