Ruby: configsig rb/tainted-format-string

Author: alexrford

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

@@ -1,19 +1,20 @@
 /**
- * Provides a taint-tracking configuration for reasoning about format
+ * Provides a taint-tracking configuration for reasoning about format string
  * injections.
  *
  *
  * Note, for performance reasons: only import this file if
- * `TaintedFormatString::Configuration` is needed, otherwise
+ * `TaintedFormatStringFlow` is needed, otherwise
  * `TaintedFormatStringCustomizations` should be imported instead.
  */
 
 private import TaintedFormatStringCustomizations::TaintedFormatString
 
 /**
- * A taint-tracking configuration for format injections.
+ * A taint-tracking configuration for format string injections.
+ * DEPRECATED: Use `TaintedFormatStringFlow`
  */
-class Configuration extends TaintTracking::Configuration {
+deprecated class Configuration extends TaintTracking::Configuration {
   Configuration() { this = "TaintedFormatString" }
 
   override predicate isSource(DataFlow::Node source) { source instanceof Source }
@@ -25,3 +26,16 @@ class Configuration extends TaintTracking::Configuration {
     node instanceof Sanitizer
   }
 }
+
+private module TaintedFormatStringConfig 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 Sanitizer }
+}
+
+/**
+ * Taint-tracking for format string injections.
+ */
+module TaintedFormatStringFlow = TaintTracking::Global<TaintedFormatStringConfig>;

ruby/ql/src/queries/security/cwe-134/TaintedFormatString.ql

@@ -13,9 +13,9 @@
 import codeql.ruby.AST
 import codeql.ruby.DataFlow
 import codeql.ruby.security.TaintedFormatStringQuery
-import DataFlow::PathGraph
+import TaintedFormatStringFlow::PathGraph
 
-from Configuration cfg, DataFlow::PathNode source, DataFlow::PathNode sink
-where cfg.hasFlowPath(source, sink)
+from TaintedFormatStringFlow::PathNode source, TaintedFormatStringFlow::PathNode sink
+where TaintedFormatStringFlow::flowPath(source, sink)
 select sink.getNode(), source, sink, "Format string depends on a $@.", source.getNode(),
   "user-provided value"