CVE-2022-30947

@@ -3,7 +3,7 @@
   <parent>
     <groupId>org.jenkins-ci.plugins</groupId>
     <artifactId>plugin</artifactId>
-    <version>3.56</version>
+    <version>4.31</version>
     <relativePath />
   </parent>
 
@@ -18,7 +18,7 @@
   <properties>
     <revision>1.14.1</revision>
     <changelist>-SNAPSHOT</changelist>
-    <jenkins.version>2.60.3</jenkins.version>
+    <jenkins.version>2.277.1</jenkins.version>
     <java.level>8</java.level>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

@@ -0,0 +1,83 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2010, Brad Larson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package hudson.plugins.repo;
+
+import hudson.AbortException;
+import jenkins.util.xml.XMLUtils;
+import org.w3c.dom.Document;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.NodeList;
+
+import org.xml.sax.SAXException;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.util.Locale;
+
+/**
+ * to validate manifest xml file and abort when remote references a local path.
+ */
+public final class ManifestValidator {
+
+    private ManifestValidator() {
+        // to hide the implicit public constructor
+    }
+
+    /**
+     * to validate manifest xml file and abort when remote references a local path.
+     * @param manifestText byte representation of manifest file
+     * @param manifestRepositoryUrl url
+     * @throws IOException when remote references a local path.
+     */
+    public static void validate(final byte[] manifestText, final String manifestRepositoryUrl)
+            throws IOException {
+        if (manifestText.length > 0) {
+            try {
+                Document doc = XMLUtils.parse(new ByteArrayInputStream(manifestText));
+                NodeList remote = doc.getElementsByTagName("remote");
+                for (int i = 0; i < remote.getLength(); i++) {
+                    NamedNodeMap attributes = remote.item(i).getAttributes();
+                    for (int j = 0; j < attributes.getLength(); j++) {
+                        if ("fetch".equals(attributes.item(j).getNodeName())
+                                && attributes.item(j).getNodeValue()
+                                .toLowerCase(Locale.ENGLISH).startsWith("file://")) {
+                                // we don't need to check source using Files.exists because fetch
+                                // attribute could resolve only local paths starting from 'file://'
+                            throw new AbortException("Checkout of Repo url '"
+                                    + manifestRepositoryUrl
+                                    + "' aborted because manifest references a local "
+                                    + "directory, which may be insecure. You can allow "
+                                    + "local checkouts anyway"
+                                    + " by setting the system property '"
+                                    + RepoScm.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.");
+                        }
+                    }
+                }
+            } catch (SAXException e) {
+                throw new IOException("Could not validate manifest");
+            }
+        }
+    }
+}

@@ -30,16 +30,20 @@
 import java.io.Serializable;
 import java.net.URL;
 import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import hudson.AbortException;
 import hudson.EnvVars;
 import hudson.Extension;
 import hudson.FilePath;
@@ -84,6 +88,17 @@ public class RepoScm extends SCM implements Serializable {
 	private static Logger debug = Logger
 			.getLogger("hudson.plugins.repo.RepoScm");
 
+	/**
+	 * escape hatch name.
+	 */
+	static final String ALLOW_LOCAL_CHECKOUT_PROPERTY =
+			RepoScm.class.getName() + ".ALLOW_LOCAL_CHECKOUT";
+	/**
+	 * escape hatch.
+	 */
+	//CS IGNORE VisibilityModifier FOR NEXT 1 LINES. REASON: escape hatch property.
+	static /* not final */ boolean ALLOW_LOCAL_CHECKOUT = Boolean.parseBoolean(System.getProperty(ALLOW_LOCAL_CHECKOUT_PROPERTY, "false"));
+
 	private final String manifestRepositoryUrl;
 
 	// Advanced Fields:
@@ -880,6 +895,10 @@ public void checkout(
 			@CheckForNull final File changelogFile, @CheckForNull final SCMRevisionState baseline)
 			throws IOException, InterruptedException {
 
+		if (!ALLOW_LOCAL_CHECKOUT && !workspace.isRemote()) {
+			abortIfUrlLocal();
+		}
+
 		Job<?, ?> job = build.getParent();
 		EnvVars env = build.getEnvironment(listener);
 		env = getEnvVars(env, job);
@@ -931,6 +950,18 @@ public void checkout(
 		build.addAction(manifestAction);
 	}
 
+	private void abortIfUrlLocal() throws AbortException {
+		if (StringUtils.isNotEmpty(manifestRepositoryUrl)
+				&& (manifestRepositoryUrl.toLowerCase(Locale.ENGLISH).startsWith("file://")
+				|| Files.exists(Paths.get(manifestRepositoryUrl)))) {
+			throw new AbortException("Checkout of Repo url '" + manifestRepositoryUrl
+					+ "' aborted because it references a local directory, "
+					+ "which may be insecure. "
+					+ "You can allow local checkouts anyway by setting the system property '"
+					+ ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.");
+		}
+	}
+
 	private int doSync(final Launcher launcher, @Nonnull final FilePath workspace,
 			final OutputStream logger, final EnvVars env)
 		throws IOException, InterruptedException {
@@ -1093,6 +1124,10 @@ private boolean checkoutCode(final Launcher launcher,
 			}
 		}
 
+		if (!ALLOW_LOCAL_CHECKOUT && !workspace.isRemote()) {
+			abortIfManifestReferencesLocalUrl(launcher, workspace, logger, env);
+		}
+
 		returnCode = doSync(launcher, workspace, logger, env);
 		if (returnCode != 0) {
 			debug.log(Level.WARNING, "Sync failed. Resetting repository");
@@ -1111,6 +1146,30 @@ private boolean checkoutCode(final Launcher launcher,
 		return true;
 	}
 
+	private byte[] getManifestAsBytes(final Launcher launcher,
+									  final FilePath workspace,
+									  final OutputStream logger,
+									  final EnvVars env)
+			throws IOException, InterruptedException {
+		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+		final List<String> commands = new ArrayList<>();
+		commands.add(getDescriptor().getExecutable());
+		commands.add("manifest");
+		launcher.launch().stderr(logger).stdout(byteArrayOutputStream).pwd(workspace)
+				.cmds(commands).envs(env).join();
+		return byteArrayOutputStream.toByteArray();
+	}
+
+	private void abortIfManifestReferencesLocalUrl(final Launcher launcher,
+												   final FilePath workspace,
+												   final OutputStream logger,
+												   final EnvVars env)
+			throws IOException, InterruptedException {
+		byte[] manifestText = getManifestAsBytes(launcher, workspace, logger, env);
+
+		ManifestValidator.validate(manifestText, manifestRepositoryUrl);
+	}
+
 	/**
 	 * Adds environmental variables for the builds to the given map.
 	 */

@@ -0,0 +1,56 @@
+package hudson.plugins.repo;
+
+import org.junit.Test;
+import org.jvnet.hudson.test.Issue;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.fail;
+
+public class ManifestValidatorTest {
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void validateWhenFetchAttributeReferencesLocalPathThenAbort() {
+        String manifest = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
+                "<manifest>\n" +
+                "  <remote  name=\"local\"\n" +
+                "           fetch=\"file:///Users/d.platonov/workdir/\"\n" +
+                "           revision=\"master\"\n" +
+                "           review=\"\" />\n" +
+                "\n" +
+                "  <project name=\"localProject\" path=\"localProject\" groups=\"lib\" remote=\"local\" />\n" +
+                "</manifest>";
+        try {
+            ManifestValidator.validate(manifest.getBytes(StandardCharsets.UTF_8), "repoUrl");
+            fail("should fail because fetch attribute in remote tag references a local path");
+        } catch (IOException e) {
+            assertThat(e.getMessage(), is("Checkout of Repo url 'repoUrl' aborted because manifest references a local directory, " +
+                    "which may be insecure. You can allow local checkouts anyway by setting the system property '" +
+                    RepoScm.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true."));
+        }
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void validateWhenValidManifestThenDoNotAbort() {
+        String manifest = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
+                "<manifest>\n" +
+                "  <remote  name=\"origin\"\n" +
+                "           fetch=\"..\"\n" + // https://stackoverflow.com/questions/18251358/repo-manifest-xml-what-does-the-fetch-mean
+                "           revision=\"master\"\n" +
+                "           review=\"https://github.com\" />\n" +
+                "\n" +
+                "  <project name=\"any\" path=\"any\" groups=\"gr\" remote=\"origin\" />\n" +
+                " </manifest>";
+
+        try {
+            ManifestValidator.validate(manifest.getBytes(StandardCharsets.UTF_8), "repoUrl");
+        } catch (Exception e) {
+            fail("fail because input is valid and no exception expected");
+        }
+    }
+}

@@ -0,0 +1,76 @@
+package hudson.plugins.repo;
+
+import hudson.model.FreeStyleBuild;
+import hudson.model.FreeStyleProject;
+import hudson.model.Result;
+import hudson.slaves.DumbSlave;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+
+public class Security2478Test {
+
+    @Rule
+    public JenkinsRule rule = new JenkinsRule();
+
+    @Rule
+    public TemporaryFolder testFolder = new TemporaryFolder();
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldAbortWhenUrlIsNonRemoteAndBuildOnController() throws Exception {
+        FreeStyleProject freeStyleProject = rule.createFreeStyleProject();
+        String manifestRepositoryUrl = testFolder.newFolder().toString();
+        RepoScm scm = new RepoScm(manifestRepositoryUrl);
+        freeStyleProject.setScm(scm);
+        FreeStyleBuild freeStyleBuild = rule.assertBuildStatus(Result.FAILURE, freeStyleProject.scheduleBuild2(0));
+        rule.assertLogContains("Checkout of Repo url '" + manifestRepositoryUrl +
+                "' aborted because it references a local directory, " +
+                "which may be insecure. You can allow local checkouts anyway by setting the system property '" +
+                RepoScm.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.", freeStyleBuild);
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldNotAbortWhenUrlIsNonRemoteAndEscapeHatchTrue() throws Exception {
+        try {
+            RepoScm.ALLOW_LOCAL_CHECKOUT = true;
+            FreeStyleProject freeStyleProject = rule.createFreeStyleProject();
+            String manifestRepositoryUrl = testFolder.newFolder().toString();
+            RepoScm scm = new RepoScm(manifestRepositoryUrl);
+            freeStyleProject.setScm(scm);
+            FreeStyleBuild freeStyleBuild = rule.assertBuildStatus(Result.FAILURE, freeStyleProject.scheduleBuild2(0));
+
+            // build fails because of manifestRepositoryUrl is not a repo(git) repository, but we don't care,
+            // we verify that build was not aborted because of RepoScm uses local path.
+            rule.assertLogNotContains("Checkout of Repo url '" + manifestRepositoryUrl +
+                    "' aborted because it references a local directory, " +
+                    "which may be insecure. You can allow local checkouts anyway by setting the system property '" +
+                    RepoScm.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.", freeStyleBuild);
+        } finally {
+            RepoScm.ALLOW_LOCAL_CHECKOUT = false;
+        }
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldNotAbortWhenUrlIsNonRemoteAndBuildOnAgent() throws Exception {
+        DumbSlave agent = rule.createOnlineSlave();
+        FreeStyleProject freeStyleProject = rule.createFreeStyleProject();
+
+        String manifestRepositoryUrl = testFolder.newFolder().toString();
+
+        RepoScm scm = new RepoScm(manifestRepositoryUrl);
+        freeStyleProject.setScm(scm);
+        freeStyleProject.setAssignedLabel(agent.getSelfLabel());
+
+        // build fails because of manifestRepositoryUrl is not a repo(git) repository, but we don't care,
+        // we verify that build was not aborted because of RepoScm uses local path.
+        rule.assertLogNotContains("Checkout of Repo url '" + manifestRepositoryUrl +
+                "' aborted because it references a local directory, " +
+                "which may be insecure. You can allow local checkouts anyway by setting the system property '" +
+                RepoScm.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.", freeStyleProject.scheduleBuild2(0).get());
+    }
+}

@@ -52,6 +52,7 @@
 import jenkins.model.Jenkins;
 import jenkins.plugins.git.GitSCMMatrixUtil;
 import jenkins.plugins.git.GitToolChooser;
+import jenkins.util.SystemProperties;
 import net.sf.json.JSONObject;
 
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -76,6 +77,8 @@
 import java.io.PrintStream;
 import java.io.Serializable;
 import java.io.Writer;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.text.MessageFormat;
 import java.util.AbstractList;
 import java.util.ArrayList;
@@ -85,6 +88,7 @@
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.logging.Level;
@@ -119,6 +123,11 @@
  */
 public class GitSCM extends GitSCMBackwardCompatibility {
 
+    static final String ALLOW_LOCAL_CHECKOUT_PROPERTY = GitSCM.class.getName() + ".ALLOW_LOCAL_CHECKOUT";
+    @SuppressFBWarnings(value = "MS_SHOULD_BE_FINAL")
+    public static /* not final */ boolean ALLOW_LOCAL_CHECKOUT =
+            SystemProperties.getBoolean(ALLOW_LOCAL_CHECKOUT_PROPERTY);
+
     /**
      * Store a config version so we're able to migrate config on various
      * functionality upgrades.
@@ -1269,6 +1278,10 @@ private boolean determineSecondFetch(CloneOption option, @NonNull RemoteConfig r
     public void checkout(Run<?, ?> build, Launcher launcher, FilePath workspace, TaskListener listener, File changelogFile, SCMRevisionState baseline)
             throws IOException, InterruptedException {
 
+        if (!ALLOW_LOCAL_CHECKOUT && !workspace.isRemote()) {
+            abortIfSourceIsLocal();
+        }
+
         if (VERBOSE)
             listener.getLogger().println("Using checkout strategy: " + getBuildChooser().getDisplayName());
 
@@ -1380,6 +1393,17 @@ public void checkout(Run<?, ?> build, Launcher launcher, FilePath workspace, Tas
         }
     }
 
+    private void abortIfSourceIsLocal() throws AbortException {
+        for (UserRemoteConfig userRemoteConfig: getUserRemoteConfigs()) {
+            String remoteUrl = userRemoteConfig.getUrl();
+            if (remoteUrl != null && (remoteUrl.toLowerCase(Locale.ENGLISH).startsWith("file://") || Files.exists(Paths.get(remoteUrl)))) {
+                throw new AbortException("Checkout of Git remote '" + remoteUrl + "' aborted because it references a local directory, " +
+                        "which may be insecure. You can allow local checkouts anyway by setting the system property '" +
+                        ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.");
+            }
+        }
+    }
+
     private void printCommitMessageToLog(TaskListener listener, GitClient git, final Build revToBuild)
             throws IOException {
         try {

@@ -5,6 +5,7 @@
 import hudson.plugins.git.GitSCM;
 import hudson.plugins.git.TestGitRepo;
 import hudson.util.StreamTaskListener;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Rule;
@@ -38,6 +39,16 @@ public void setUp() throws Exception {
 		before();
 	}
 
+	@Before
+	public void allowNonRemoteCheckout() {
+		GitSCM.ALLOW_LOCAL_CHECKOUT = true;
+	}
+
+	@After
+	public void disallowNonRemoteCheckout() {
+		GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+	}
+
 	protected abstract void before() throws Exception;
 
 	/**

@@ -28,12 +28,14 @@
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import hudson.plugins.git.GitSCM;
 import org.apache.commons.io.FileUtils;
 import org.jenkinsci.plugins.gitclient.GitClient;
 import org.jenkinsci.plugins.gitclient.TestCliGitAPIImpl;
 import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
 import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
@@ -63,6 +65,16 @@ public void setup() throws Exception {
         listener = new LogTaskListener(Logger.getLogger("prune tags"), Level.FINEST);
     }
 
+    @Before
+    public void allowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = true;
+    }
+
+    @After
+    public void disallowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+    }
+
     @Issue("JENKINS-61869")
     @Test
     public void verify_that_local_tag_is_pruned_when_not_exist_on_remote_using_pipeline() throws Exception {

@@ -0,0 +1,77 @@
+package hudson.plugins.git;
+
+import hudson.model.Result;
+import jenkins.plugins.git.GitSampleRepoRule;
+import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
+import org.jenkinsci.plugins.workflow.job.WorkflowJob;
+import org.jenkinsci.plugins.workflow.job.WorkflowRun;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+
+import java.io.File;
+
+import static org.junit.Assert.assertFalse;
+
+public class Security2478Test {
+
+    @Rule
+    public JenkinsRule rule = new JenkinsRule();
+
+    @Rule
+    public GitSampleRepoRule sampleRepo = new GitSampleRepoRule();
+
+
+    @Before
+    public void setUpAllowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+    }
+
+    @After
+    public void disallowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldNotAbortWhenLocalSourceAndRunningOnAgent() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", GitSCM.ALLOW_LOCAL_CHECKOUT);
+        rule.createOnlineSlave();
+        sampleRepo.init();
+        sampleRepo.write("file", "v1");
+        sampleRepo.git("commit", "--all", "--message=test commit");
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+
+        String script = "node('slave0') {\n" +
+                "   checkout([$class: 'GitSCM', branches: [[name: '*/master']], extensions: [], userRemoteConfigs: [[url: '" + sampleRepo.fileUrl() + "', credentialsId: '']]])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        WorkflowRun run = rule.assertBuildStatus(Result.SUCCESS, p.scheduleBuild2(0));
+        rule.assertLogNotContains("aborted because it references a local directory, which may be insecure. " +
+                "You can allow local checkouts anyway by setting the system property 'hudson.plugins.git.GitSCM.ALLOW_LOCAL_CHECKOUT' to true.", run);
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldAbortWhenSourceIsNonRemoteAndRunningOnController() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", GitSCM.ALLOW_LOCAL_CHECKOUT);
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+        String workspaceDir = rule.jenkins.getRootDir().getAbsolutePath();
+
+        String path = "file://" + workspaceDir + File.separator + "jobName@script" + File.separator + "anyhmachash";
+        String escapedPath = path.replace("\\", "\\\\"); // for windows
+        String script = "node {\n" +
+                "   checkout([$class: 'GitSCM', branches: [[name: '*/main']], extensions: [], userRemoteConfigs: [[" +
+                "url: '" + escapedPath + "'," +
+                " credentialsId: '']]])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        WorkflowRun run = rule.assertBuildStatus(Result.FAILURE, p.scheduleBuild2(0));
+        rule.assertLogContains("Checkout of Git remote '" + path + "' " +
+                        "aborted because it references a local directory, which may be insecure. " +
+                        "You can allow local checkouts anyway by setting the system property 'hudson.plugins.git.GitSCM.ALLOW_LOCAL_CHECKOUT' to true.", run);
+    }
+}

@@ -28,6 +28,7 @@
 import com.gargoylesoftware.htmlunit.util.NameValuePair;
 import hudson.Launcher;
 import hudson.model.TaskListener;
+import hudson.plugins.git.GitSCM;
 import hudson.util.StreamTaskListener;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -48,6 +49,16 @@ public final class GitSampleRepoRule extends AbstractSampleDVCSRepoRule {
 
     private static final Logger LOGGER = Logger.getLogger(GitSampleRepoRule.class.getName());
 
+    protected void before() throws Throwable {
+        super.before();
+        GitSCM.ALLOW_LOCAL_CHECKOUT = true;
+    }
+
+    protected void after() {
+        super.after();
+        GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+    }
+
     public void git(String... cmds) throws Exception {
         run("git", cmds);
     }

@@ -3,10 +3,12 @@
 import hudson.model.Job;
 import hudson.model.Queue;
 import hudson.model.Run;
+import hudson.plugins.git.GitSCM;
 import hudson.plugins.git.util.BuildData;
 import jenkins.model.ParameterizedJobMixIn;
 import org.jenkinsci.plugins.gitclient.Git;
 import org.jenkinsci.plugins.gitclient.GitClient;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -48,6 +50,16 @@ public void setUp() throws IOException, InterruptedException {
         repo.init();
     }
 
+    @Before
+    public void allowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = true;
+    }
+
+    @After
+    public void disallowNonRemoteCheckout() {
+        GitSCM.ALLOW_LOCAL_CHECKOUT = false;
+    }
+
     @Test
     public void commitWithoutTagShouldNotExportMessage() throws Exception {
         // Given a git repo without any tags

@@ -11,6 +11,7 @@
 import hudson.Extension;
 import hudson.FilePath;
 import hudson.Launcher;
+import hudson.Main;
 import hudson.Util;
 import hudson.matrix.MatrixRun;
 import hudson.model.AbstractBuild;
@@ -50,8 +51,11 @@
 import java.io.Serializable;
 import java.net.MalformedURLException;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.logging.Level;
@@ -62,6 +66,7 @@
 import edu.umd.cs.findbugs.annotations.NonNull;
 import jenkins.model.Jenkins;
 import net.sf.json.JSONObject;
+import org.apache.commons.lang.StringUtils;
 import org.ini4j.Ini;
 import org.kohsuke.stapler.AncestorInPath;
 import org.kohsuke.stapler.DataBoundConstructor;
@@ -74,6 +79,11 @@
  */
 public class MercurialSCM extends SCM implements Serializable {
 
+    static final String ALLOW_LOCAL_CHECKOUT_PROPERTY = MercurialSCM.class.getName() + ".ALLOW_LOCAL_CHECKOUT";
+    //TODO: use SystemProperties instead after jenkins version upgrade to 2.236
+    static /* not final */ boolean ALLOW_LOCAL_CHECKOUT =
+            Boolean.parseBoolean(System.getProperty(ALLOW_LOCAL_CHECKOUT_PROPERTY, String.valueOf(Main.isUnitTest)));
+
     // Environment vars names to be exposed
     private static final String ENV_MERCURIAL_REVISION = "MERCURIAL_REVISION";
     private static final String ENV_MERCURIAL_REVISION_SHORT = "MERCURIAL_REVISION_SHORT";
@@ -561,6 +571,11 @@ public void checkout(Run<?, ?> build, Launcher launcher, FilePath workspace, fin
             throws IOException, InterruptedException {
 
         MercurialInstallation mercurialInstallation = findInstallation(installation);
+
+        if (!ALLOW_LOCAL_CHECKOUT && !workspace.isRemote()) {
+            abortIfSourceLocal();
+        }
+
         final boolean jobShouldUseSharing = mercurialInstallation != null && mercurialInstallation.isUseSharing();
 
         Node node = workspaceToNode(workspace);
@@ -596,7 +611,15 @@ public void checkout(Run<?, ?> build, Launcher launcher, FilePath workspace, fin
         }
         }
     }
-    
+
+    private void abortIfSourceLocal() throws IOException {
+        if (StringUtils.isNotEmpty(source) &&
+                (source.toLowerCase(Locale.ENGLISH).startsWith("file://") || Files.exists(Paths.get(source)))) {
+
+            throw new AbortException("Checkout of Mercurial source '" + source + "' aborted because it references a local directory, which may be insecure. You can allow local checkouts anyway by setting the system property '" + ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.");
+        }
+    }
+
     private boolean canReuseWorkspace(FilePath repo, Node node,
             boolean jobShouldUseSharing, Run<?,?> build,
             Launcher launcher, TaskListener listener)

@@ -0,0 +1,117 @@
+package hudson.plugins.mercurial;
+
+import hudson.FilePath;
+import hudson.model.Result;
+import hudson.slaves.DumbSlave;
+import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
+import org.jenkinsci.plugins.workflow.job.WorkflowJob;
+import org.jenkinsci.plugins.workflow.job.WorkflowRun;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.rules.TestRule;
+import org.jvnet.hudson.test.FlagRule;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+
+import java.io.File;
+import java.util.Collections;
+
+import static org.junit.Assert.assertFalse;
+
+public class Security2478Test {
+
+    private static final String INSTALLATION = "mercurial";
+
+    @Rule
+    public JenkinsRule rule = new JenkinsRule();
+    @Rule
+    public MercurialRule m = new MercurialRule(rule);
+
+    @Rule
+    public TestRule notAllowNonRemoteCheckout = new FlagRule<>(() -> MercurialSCM.ALLOW_LOCAL_CHECKOUT, x -> MercurialSCM.ALLOW_LOCAL_CHECKOUT = x, false);
+
+    @Rule
+    public TemporaryFolder tmp = new TemporaryFolder();
+    private File repo;
+
+    @Before
+    public void setUp() throws Exception {
+        repo = tmp.getRoot();
+        rule.jenkins
+                .getDescriptorByType(MercurialInstallation.DescriptorImpl.class)
+                .setInstallations(new MercurialInstallation(INSTALLATION, "", "hg",
+                        false, true, new File(tmp.newFolder(),"custom-dir").getAbsolutePath(), false, "",
+                        Collections.emptyList()));
+
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldAbortWhenSourceIsNonRemoteAndBuildOnController() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", MercurialSCM.ALLOW_LOCAL_CHECKOUT);
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+        FilePath sourcePath = rule.jenkins.getRootPath().createTempDir("t", "");
+        String script = "node {\n" +
+                "checkout([$class: 'MercurialSCM', credentialsId: '', installation: 'mercurial', source: '" + sourcePath + "'])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        WorkflowRun run = rule.assertBuildStatus(Result.FAILURE, p.scheduleBuild2(0));
+        rule.assertLogContains("Checkout of Mercurial source '" + sourcePath + "' aborted because it references a local directory, which may be insecure. You can allow local checkouts anyway by setting the system property '" + MercurialSCM.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.", run);
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutOnAgentShouldNotAbortWhenSourceIsNonRemoteAndBuildOnAgent() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", MercurialSCM.ALLOW_LOCAL_CHECKOUT);
+        DumbSlave agent = rule.createOnlineSlave();
+        FilePath workspace = agent.getRootPath().createTempDir("t", "");
+        m.hg(workspace, "init");
+        m.touchAndCommit(workspace, "a");
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+        String script = "node('slave0') {\n" +
+                "checkout([$class: 'MercurialSCM', credentialsId: '', installation: 'mercurial', source: '" + workspace + "'])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        rule.assertBuildStatus(Result.SUCCESS, p.scheduleBuild2(0));
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldNotAbortWhenSourceIsAlias() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", MercurialSCM.ALLOW_LOCAL_CHECKOUT);
+
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+        String aliasName = "alias1";
+        // configure mercurial installation with an alias in a path
+        rule.jenkins.getDescriptorByType(MercurialInstallation.DescriptorImpl.class).setInstallations(new MercurialInstallation("mercurial", "", "hg", false, false,"", false, "[paths]\n" + aliasName + " = https://www.mercurial-scm.org/repo/hello", null));
+        String script = "node {\n" +
+                "checkout([$class: 'MercurialSCM', credentialsId: '', installation: 'mercurial', source: '" + aliasName + "'])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        m.hg(new FilePath(repo), "init");
+        m.touchAndCommit(new FilePath(repo), "a");
+        WorkflowRun run = rule.assertBuildStatus(Result.SUCCESS, p.scheduleBuild2(0));
+        rule.assertLogNotContains("Checkout of Mercurial source '" + aliasName + "' aborted because it references a local directory, which may be insecure. You can allow local checkouts anyway by setting the system property '" + MercurialSCM.ALLOW_LOCAL_CHECKOUT_PROPERTY + "' to true.", run);
+
+    }
+
+    @Issue("SECURITY-2478")
+    @Test
+    public void checkoutShouldNotAbortWhenSourceIsAliasPointingToLocalPath() throws Exception {
+        assertFalse("Non Remote checkout should be disallowed", MercurialSCM.ALLOW_LOCAL_CHECKOUT);
+
+        WorkflowJob p = rule.jenkins.createProject(WorkflowJob.class, "pipeline");
+        String aliasName = "alias1";
+        // configure mercurial installation with an alias in a path
+        rule.jenkins.getDescriptorByType(MercurialInstallation.DescriptorImpl.class).setInstallations(new MercurialInstallation("mercurial", "", "hg", false, false,"", false, "[paths]\n" + aliasName + " = " + repo.getPath(), null));
+        String script = "node {\n" +
+                "checkout([$class: 'MercurialSCM', credentialsId: '', installation: 'mercurial', source: 'alias1'])\n" +
+                "}";
+        p.setDefinition(new CpsFlowDefinition(script, true));
+        m.hg(new FilePath(repo), "init");
+        m.touchAndCommit(new FilePath(repo), "a");
+        rule.assertBuildStatus(Result.SUCCESS, p.scheduleBuild2(0));
+    }
+}