kenhuuu commented on code in PR #3402: URL: https://github.com/apache/tinkerpop/pull/3402#discussion_r3205176114
########## gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/language/grammar/ParameterMapVisitor.java: ########## @@ -0,0 +1,102 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.tinkerpop.gremlin.language.grammar; + +/** + * A visitor for parsing parameter map strings that prevents traversal injection. + * <p> + * Extends {@link GenericLiteralVisitor} and overrides traversal-related visit methods + * to throw, ensuring that no traversal can be constructed or executed during the + * parameter map parsing walk. This is critical for security because + * {@code visitTerminatedTraversal} in the base class would execute the traversal + * immediately via {@link TraversalTerminalMethodVisitor}. + */ +public class ParameterMapVisitor extends GenericLiteralVisitor { + + private static final int DEFAULT_MAX_NESTING_DEPTH = 32; + + private final int maxNestingDepth; + private int currentNestingDepth = 0; + + public ParameterMapVisitor(final GremlinAntlrToJava antlr) { + this(antlr, DEFAULT_MAX_NESTING_DEPTH); + } + + public ParameterMapVisitor(final GremlinAntlrToJava antlr, final int maxNestingDepth) { + super(antlr); + this.maxNestingDepth = maxNestingDepth; + } + + /** + * Overridden to prevent nested traversal construction in parameter maps. + */ + @Override + public Object visitNestedTraversal(final GremlinParser.NestedTraversalContext ctx) { + throw new GremlinParserException("Traversals are not allowed in parameter maps"); + } + + /** + * Overridden to prevent terminated traversal execution in parameter maps. + * This is the critical override because the base class would execute the traversal + * immediately via {@link TraversalTerminalMethodVisitor}. + */ + @Override + public Object visitTerminatedTraversal(final GremlinParser.TerminatedTraversalContext ctx) { + throw new GremlinParserException("Traversals are not allowed in parameter maps"); + } + + @Override + public Object visitGenericMapLiteral(final GremlinParser.GenericMapLiteralContext ctx) { + currentNestingDepth++; + if (currentNestingDepth > maxNestingDepth) { + throw new GremlinParserException("Parameter map nesting depth exceeds maximum of " + maxNestingDepth); + } + try { + return super.visitGenericMapLiteral(ctx); + } finally { + currentNestingDepth--; + } + } + + @Override + public Object visitGenericCollectionLiteral(final GremlinParser.GenericCollectionLiteralContext ctx) { + currentNestingDepth++; + if (currentNestingDepth > maxNestingDepth) { + throw new GremlinParserException("Parameter map nesting depth exceeds maximum of " + maxNestingDepth); + } + try { + return super.visitGenericCollectionLiteral(ctx); Review Comment: Yes, thanks for pointing this out, something is definitely not right here. I modified the test in ParameterMapVisitorTest slightly to assert the exception message and it confirms that it isn't dispatching to the right visitor. I'll have to think about how to make a simple change to fix this. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
