This is an automated email from the ASF dual-hosted git repository. lukaszlenart pushed a commit to branch WW-5666-input-length-limits-6x in repository https://gitbox.apache.org/repos/asf/struts.git
commit 34ab0c8ede2e161f5e57995d189b790fcadab856 Author: Lukasz Lenart <[email protected]> AuthorDate: Fri Jul 31 11:11:56 2026 +0200 WW-5666 fix(core): bound the CSP report body read and make the limit configurable CspReportAction read the submitted report body with a single readLine() and had no limit of its own. Read it up to a limit instead, defaulting to 8192 characters and configurable through struts.csp.report.maxSize. A body above the limit is discarded with a warning rather than processed. The limit is injected when the action is built, before the interceptor stack runs, because withServletRequest is invoked by the servletConfig interceptor ahead of staticParams and params. Values that are not usable as a buffer size are ignored with a warning. --- .../java/org/apache/struts2/StrutsConstants.java | 7 + .../org/apache/struts2/action/CspReportAction.java | 85 +++++++++- .../org/apache/struts2/default.properties | 4 + .../action/CspReportActionReportSizeTest.java | 185 +++++++++++++++++++++ 4 files changed, 278 insertions(+), 3 deletions(-) diff --git a/core/src/main/java/org/apache/struts2/StrutsConstants.java b/core/src/main/java/org/apache/struts2/StrutsConstants.java index 0ac751640..7138aa3c7 100644 --- a/core/src/main/java/org/apache/struts2/StrutsConstants.java +++ b/core/src/main/java/org/apache/struts2/StrutsConstants.java @@ -518,6 +518,13 @@ public final class StrutsConstants { public static final String STRUTS_CSP_NONCE_READER = "struts.csp.nonce.reader"; public static final String STRUTS_CSP_NONCE_SOURCE = "struts.csp.nonce.source"; + /** + * See {@link org.apache.struts2.action.CspReportAction} + * + * @since 6.11.0 + */ + public static final String STRUTS_CSP_REPORT_MAX_SIZE = "struts.csp.report.maxSize"; + /** * Specifies the type of cache to use for proxy detection in ProxyUtil. * Valid values defined in {@link com.opensymphony.xwork2.ognl.OgnlCacheFactory.CacheType}. diff --git a/core/src/main/java/org/apache/struts2/action/CspReportAction.java b/core/src/main/java/org/apache/struts2/action/CspReportAction.java index 5d6990a80..7c272cdcc 100644 --- a/core/src/main/java/org/apache/struts2/action/CspReportAction.java +++ b/core/src/main/java/org/apache/struts2/action/CspReportAction.java @@ -19,11 +19,16 @@ package org.apache.struts2.action; import com.opensymphony.xwork2.ActionSupport; +import com.opensymphony.xwork2.inject.Inject; +import org.apache.commons.lang3.StringUtils; +import org.apache.logging.log4j.LogManager; +import org.apache.logging.log4j.Logger; +import org.apache.struts2.StrutsConstants; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; -import java.io.BufferedReader; import java.io.IOException; +import java.io.Reader; import static org.apache.struts2.interceptor.csp.CspSettings.CSP_REPORT_TYPE; @@ -51,7 +56,58 @@ import static org.apache.struts2.interceptor.csp.CspSettings.CSP_REPORT_TYPE; * @see DefaultCspReportAction */ public abstract class CspReportAction extends ActionSupport implements ServletRequestAware, ServletResponseAware { + + private static final Logger LOG = LogManager.getLogger(CspReportAction.class); + + /** + * Default upper bound, in characters, on the report body accepted by {@link #withServletRequest}. + * CSP violation reports are small JSON documents; anything larger is not treated as a report. + */ + public static final int DEFAULT_MAX_REPORT_SIZE = 8192; + + /** + * Largest value accepted for {@code struts.csp.report.maxSize}. A configured value above this is + * ignored, so that a mistyped setting cannot size a per-request buffer large enough to exhaust + * memory. + */ + private static final int MAX_REPORT_SIZE_LIMIT = 1024 * 1024; + private HttpServletRequest request; + private int maxReportSize = DEFAULT_MAX_REPORT_SIZE; + + /** + * Sets the upper bound, in characters, on an accepted report body. A body exceeding this size is + * discarded and not passed to {@link #processReport(String)}. + * <p> + * The value is injected from {@code struts.csp.report.maxSize} when the action is built, which is + * before the interceptor stack runs. It is deliberately not an action property: the report body is + * read by {@link #withServletRequest(HttpServletRequest)}, which the {@code servletConfig} + * interceptor invokes ahead of {@code staticParams} and {@code params}, so a value applied by + * either of those would arrive too late to have any effect. + * + * @param maxReportSize maximum accepted report size in characters + * @since 6.11.0 + */ + @Inject(value = StrutsConstants.STRUTS_CSP_REPORT_MAX_SIZE, required = false) + public void setMaxReportSize(String maxReportSize) { + if (StringUtils.isBlank(maxReportSize)) { + return; + } + int size; + try { + size = Integer.parseInt(maxReportSize.trim()); + } catch (NumberFormatException e) { + LOG.warn("Ignoring non-numeric {} value: {}, keeping {}", + StrutsConstants.STRUTS_CSP_REPORT_MAX_SIZE, maxReportSize, this.maxReportSize); + return; + } + if (size < 1 || size > MAX_REPORT_SIZE_LIMIT) { + LOG.warn("Ignoring out-of-range {} value: {}, expected 1..{}, keeping {}", + StrutsConstants.STRUTS_CSP_REPORT_MAX_SIZE, size, MAX_REPORT_SIZE_LIMIT, this.maxReportSize); + return; + } + this.maxReportSize = size; + } @Override public void withServletRequest(HttpServletRequest request) { @@ -60,13 +116,36 @@ public abstract class CspReportAction extends ActionSupport implements ServletRe } try { - BufferedReader reader = request.getReader(); - String cspReport = reader.readLine(); + String cspReport = readReport(request.getReader()); + if (cspReport == null) { + LOG.warn("Discarding CSP report larger than the configured limit of {} characters", maxReportSize); + return; + } processReport(cspReport); } catch (IOException ignored) { } } + /** + * Reads at most {@link #maxReportSize} characters from the report body. + * + * @param reader reader over the report body + * @return the report body, or {@code null} if it exceeds the limit + * @throws IOException if the body cannot be read + */ + private String readReport(Reader reader) throws IOException { + char[] buffer = new char[maxReportSize]; + int total = 0; + int read; + while (total < buffer.length && (read = reader.read(buffer, total, buffer.length - total)) != -1) { + total += read; + } + if (total == buffer.length && reader.read() != -1) { + return null; + } + return new String(buffer, 0, total); + } + private boolean isCspReportRequest(HttpServletRequest request) { if (!"POST".equals(request.getMethod()) || request.getContentLength() <= 0){ return false; diff --git a/core/src/main/resources/org/apache/struts2/default.properties b/core/src/main/resources/org/apache/struts2/default.properties index 3eedc2437..2ab573b87 100644 --- a/core/src/main/resources/org/apache/struts2/default.properties +++ b/core/src/main/resources/org/apache/struts2/default.properties @@ -290,4 +290,8 @@ struts.url.decoder=strutsUrlDecoder ### Defines source to read nonce value from, possible values are: request, session struts.csp.nonceSource=session +### Maximum size, in characters, of a CSP violation report accepted by CspReportAction +### Reports larger than this are discarded. Values outside 1..1048576 are ignored. +struts.csp.report.maxSize=8192 + ### END SNIPPET: complete_file diff --git a/core/src/test/java/org/apache/struts2/action/CspReportActionReportSizeTest.java b/core/src/test/java/org/apache/struts2/action/CspReportActionReportSizeTest.java new file mode 100644 index 000000000..41c2b7994 --- /dev/null +++ b/core/src/test/java/org/apache/struts2/action/CspReportActionReportSizeTest.java @@ -0,0 +1,185 @@ +/* + * 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.struts2.action; + +import com.opensymphony.xwork2.XWorkTestCase; +import org.apache.struts2.StrutsConstants; +import org.apache.struts2.interceptor.csp.CspSettings; +import org.springframework.mock.web.MockHttpServletRequest; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStream; +import java.io.Reader; +import java.util.Properties; +import java.util.concurrent.atomic.AtomicLong; + +/** + * Verifies that {@link CspReportAction} applies an upper bound to the report body it accepts, and + * that the bound is configurable. + */ +public class CspReportActionReportSizeTest extends XWorkTestCase { + + /** + * The reader supplied by the container buffers ahead, so consumption is bounded by the limit + * plus one buffer rather than by the limit exactly. That overshoot is fixed, not proportional + * to the size of the body. + */ + private static final long READ_AHEAD_ALLOWANCE = 8192L; + + /** + * Produces {@code total} characters without buffering them, and records how many the caller + * actually consumed. + */ + private static final class CountingReader extends Reader { + private final long total; + private final AtomicLong consumed; + private long produced = 0; + + CountingReader(long total, AtomicLong consumed) { + this.total = total; + this.consumed = consumed; + } + + @Override + public int read(char[] cbuf, int off, int len) { + if (produced >= total) { + return -1; + } + int count = (int) Math.min(len, total - produced); + for (int i = 0; i < count; i++) { + cbuf[off + i] = 'a'; + } + produced += count; + consumed.addAndGet(count); + return count; + } + + @Override + public void close() { + // characters are generated on demand, so there is nothing to release + } + } + + private static final class CapturingCspReportAction extends CspReportAction { + String captured; + int reports; + + @Override + void processReport(String jsonCspReport) { + captured = jsonCspReport; + reports++; + } + } + + /** + * A request that both declares and delivers {@code size} characters, matching what a client can + * actually send: the declared length and the delivered body agree. + */ + private MockHttpServletRequest requestOfSize(final long size, final AtomicLong consumed) { + MockHttpServletRequest request = new MockHttpServletRequest("POST", "/csp-reports") { + @Override + public int getContentLength() { + return (int) Math.min(size, Integer.MAX_VALUE); + } + + @Override + public BufferedReader getReader() { + return new BufferedReader(new CountingReader(size, consumed)); + } + }; + request.setContentType(CspSettings.CSP_REPORT_TYPE); + return request; + } + + public void testReportAboveLimitIsNotProcessed() { + AtomicLong consumed = new AtomicLong(); + MockHttpServletRequest request = requestOfSize(64L * 1024 * 1024, consumed); + + CapturingCspReportAction action = new CapturingCspReportAction(); + action.withServletRequest(request); + + assertEquals("A report above the limit should not be processed", 0, action.reports); + assertTrue("Consumed " + consumed.get() + " characters for a limit of " + + CspReportAction.DEFAULT_MAX_REPORT_SIZE, + consumed.get() <= CspReportAction.DEFAULT_MAX_REPORT_SIZE + READ_AHEAD_ALLOWANCE); + } + + public void testReportWithinLimitIsProcessed() { + String sampleReport = "{\"csp-report\":{\"document-uri\":\"https://example.test/\"}}";; + MockHttpServletRequest request = new MockHttpServletRequest("POST", "/csp-reports"); + request.setContent(sampleReport.getBytes()); + request.setContentType(CspSettings.CSP_REPORT_TYPE); + + CapturingCspReportAction action = new CapturingCspReportAction(); + action.withServletRequest(request); + + assertEquals("A report within the limit should be processed", 1, action.reports); + assertEquals("The report should be passed through unchanged", sampleReport, action.captured); + } + + public void testConfiguredLimitIsApplied() { + AtomicLong consumed = new AtomicLong(); + MockHttpServletRequest request = requestOfSize(4096, consumed); + + CapturingCspReportAction action = new CapturingCspReportAction(); + action.setMaxReportSize("1024"); + action.withServletRequest(request); + + assertEquals("A report above the configured limit should not be processed", 0, action.reports); + assertTrue("Consumed " + consumed.get() + " characters for a configured limit of 1024", + consumed.get() <= 1024L + READ_AHEAD_ALLOWANCE); + } + + /** + * The key named by {@link StrutsConstants#STRUTS_CSP_REPORT_MAX_SIZE} must exist in + * default.properties under exactly that name. If the two drift apart the value is silently never + * injected, leaving the limit hard-coded and the documented setting inert. + */ + public void testLimitKeyIsDefinedInDefaultProperties() throws IOException { + Properties defaults = new Properties(); + try (InputStream in = getClass().getClassLoader() + .getResourceAsStream("org/apache/struts2/default.properties")) { + assertNotNull("default.properties should be on the classpath", in); + defaults.load(in); + } + + assertEquals(StrutsConstants.STRUTS_CSP_REPORT_MAX_SIZE + " should be defined in default.properties", + String.valueOf(CspReportAction.DEFAULT_MAX_REPORT_SIZE), + defaults.getProperty(StrutsConstants.STRUTS_CSP_REPORT_MAX_SIZE)); + } + + public void testUnusableConfiguredValuesAreIgnored() { + String[] unusable = {"", " ", "not-a-number", "0", "-1", "2147483647"}; + + for (String value : unusable) { + AtomicLong consumed = new AtomicLong(); + MockHttpServletRequest request = requestOfSize(64L * 1024 * 1024, consumed); + + CapturingCspReportAction action = new CapturingCspReportAction(); + action.setMaxReportSize(value); + action.withServletRequest(request); + + assertEquals("A report above the default limit should not be processed for value '" + + value + "'", 0, action.reports); + assertTrue("Consumed " + consumed.get() + " characters for value '" + value + "'", + consumed.get() <= CspReportAction.DEFAULT_MAX_REPORT_SIZE + READ_AHEAD_ALLOWANCE); + } + } +}
