Ruby: configsig rb/html-constructed-from-input

Author: alexrford

ruby/ql/lib/codeql/ruby/security/UnsafeHtmlConstructionQuery.qll

@@ -2,8 +2,9 @@
  * Provides a taint-tracking configuration for reasoning about HTML
  * constructed from library input vulnerabilities.
  *
- * Note, for performance reasons: only import this file if `Configuration` is needed,
- * otherwise `UnsafeHtmlConstructionCustomizations` should be imported instead.
+ * Note, for performance reasons: only import this file if
+ * `UnsafeHtmlConstructionFlow` is needed, otherwise
+ * `UnsafeHtmlConstructionCustomizations` should be imported instead.
  */
 
 import codeql.ruby.DataFlow
@@ -13,8 +14,9 @@ private import codeql.ruby.dataflow.BarrierGuards
 
 /**
  * A taint-tracking configuration for detecting unsafe HTML construction.
+ * DEPRECATED: Use `UnsafeHtmlConstructionFlow`
  */
-class Configuration extends TaintTracking::Configuration {
+deprecated class Configuration extends TaintTracking::Configuration {
   Configuration() { this = "UnsafeHtmlConstruction" }
 
   override predicate isSource(DataFlow::Node source) { source instanceof Source }
@@ -31,3 +33,22 @@ class Configuration extends TaintTracking::Configuration {
     result instanceof DataFlow::FeatureHasSourceCallContext
   }
 }
+
+private module UnsafeHtmlConstructionConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source instanceof Source }
+
+  predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
+
+  predicate isBarrier(DataFlow::Node node) {
+    node instanceof StringConstCompareBarrier or
+    node instanceof StringConstArrayInclusionCallBarrier
+  }
+
+  // override to require the path doesn't have unmatched return steps
+  DataFlow::FlowFeature getAFeature() { result instanceof DataFlow::FeatureHasSourceCallContext }
+}
+
+/**
+ * Taint-tracking for detecting unsafe HTML construction.
+ */
+module UnsafeHtmlConstructionFlow = TaintTracking::Global<UnsafeHtmlConstructionConfig>;

ruby/ql/src/queries/security/cwe-079/UnsafeHtmlConstruction.ql

@@ -13,10 +13,12 @@
  */
 
 import codeql.ruby.security.UnsafeHtmlConstructionQuery
-import DataFlow::PathGraph
+import UnsafeHtmlConstructionFlow::PathGraph
 
-from DataFlow::Configuration cfg, DataFlow::PathNode source, DataFlow::PathNode sink, Sink sinkNode
-where cfg.hasFlowPath(source, sink) and sink.getNode() = sinkNode
+from
+  UnsafeHtmlConstructionFlow::PathNode source, UnsafeHtmlConstructionFlow::PathNode sink,
+  Sink sinkNode
+where UnsafeHtmlConstructionFlow::flowPath(source, sink) and sink.getNode() = sinkNode
 select sinkNode, source, sink,
   "This " + sinkNode.getSinkType() + " which depends on $@ might later allow $@.", source.getNode(),
   "library input", sinkNode.getXssSink(), "cross-site scripting"