*)update XQueryInjectionLib.qll

Author: haby0

java/ql/src/Security/CWE/CWE-652/XQueryInjectionLib.qll

@@ -1,35 +1,90 @@
 import java
 import semmle.code.java.dataflow.FlowSources
+import semmle.code.java.dataflow.TaintTracking2
+import DataFlow::PathGraph
 
-class XQueryInjectionConfig extends TaintTracking::Configuration {
-  XQueryInjectionConfig() { this = "XQueryInjectionConfig" }
+/** A call to `XQConnection.prepareExpression`. */
+class XQueryParserCall extends MethodAccess {
+  XQueryParserCall() {
+    exists(Method m |
+      this.getMethod() = m and
+      m.getDeclaringType()
+          .getASourceSupertype*()
+          .hasQualifiedName("javax.xml.xquery", "XQConnection") and
+      m.hasName("prepareExpression")
+    )
+  }
+  // return the first parameter of the `bindString` method and use it as a sink
+  Expr getSink() { result = this.getArgument(0) }
+}
+
+/** A call to `XQDynamicContext.bindString`. */
+class XQueryBindStringCall extends MethodAccess {
+  XQueryBindStringCall() {
+    exists(Method m |
+      this.getMethod() = m and
+      m.getDeclaringType()
+          .getASourceSupertype*()
+          .hasQualifiedName("javax.xml.xquery", "XQDynamicContext") and
+      m.hasName("bindString")
+    )
+  }
+  // return the second parameter of the `bindString` method and use it as a sink
+  Expr getSink() { result = this.getArgument(1) }
+}
+
+/** Used to determine whether to call the `prepareExpression` method, and the first parameter value can be remotely controlled. */
+class ParserParameterRemoteFlowConf extends TaintTracking2::Configuration {
+  ParserParameterRemoteFlowConf() { this = "ParserParameterRemoteFlowConf" }
 
-  override predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
+  override predicate isSource(DataFlow::Node src) { src instanceof RemoteFlowSource }
 
-  override predicate isSink(DataFlow::Node sink) { sink instanceof XQueryInjectionSink }
+  override predicate isSink(DataFlow::Node sink) {
+    exists(XQueryParserCall xqpc | xqpc.getSink() = sink.asExpr())
+  }
 }
 
-/*Find if the executeQuery method is finally called.*/
-predicate executeQuery(MethodAccess ma) {
-  exists(LocalVariableDeclExpr lvd, MethodAccess ma1, Method m | lvd.getAChildExpr() = ma |
-    m = ma1.getMethod() and
-    m.hasName("executeQuery") and
-    m.getDeclaringType()
-        .getASourceSupertype*()
-        .hasQualifiedName("javax.xml.xquery", "XQPreparedExpression") and
-    ma1.getQualifier() = lvd.getAnAccess()
-  )
+/** Used to determine whether to call the `bindString` method, and the second parameter value can be controlled remotely. */
+class BindParameterRemoteFlowConf extends TaintTracking2::Configuration {
+  BindParameterRemoteFlowConf() { this = "BindParameterRemoteFlowConf" }
+
+  override predicate isSource(DataFlow::Node src) { src instanceof RemoteFlowSource }
+
+  override predicate isSink(DataFlow::Node sink) {
+    exists(XQueryBindStringCall xqbsc | xqbsc.getSink() = sink.asExpr())
+  }
 }
 
-class XQueryInjectionSink extends DataFlow::ExprNode {
-  XQueryInjectionSink() {
-    exists(MethodAccess ma, Method m | m = ma.getMethod() |
+/**
+ * A data flow source for XQuery injection vulnerability.
+ *  1. `prepareExpression` call as sink.
+ *  2. Determine whether the `var1` parameter of `prepareExpression` method can be controlled remotely.
+ */
+class XQueryInjectionSource extends DataFlow::ExprNode {
+  XQueryInjectionSource() {
+    exists(MethodAccess ma, Method m, ParserParameterRemoteFlowConf conf, DataFlow::Node node |
+      m = ma.getMethod()
+    |
       m.hasName("prepareExpression") and
       m.getDeclaringType()
           .getASourceSupertype*()
           .hasQualifiedName("javax.xml.xquery", "XQConnection") and
-      executeQuery(ma) and
-      asExpr() = ma.getArgument(0)
+      asExpr() = ma and
+      node.asExpr() = ma.getArgument(0) and
+      conf.hasFlowTo(node)
+    )
+  }
+}
+
+/** A data flow sink for XQuery injection vulnerability. */
+class XQueryInjectionSink extends DataFlow::Node {
+  XQueryInjectionSink() {
+    exists(MethodAccess ma, Method m | m = ma.getMethod() |
+      m.hasName("executeQuery") and
+      m.getDeclaringType()
+          .getASourceSupertype*()
+          .hasQualifiedName("javax.xml.xquery", "XQPreparedExpression") and
+      asExpr() = ma.getQualifier()
     )
   }
 }