partialpathtraversalvulnerability.md

Partial path traversal vulnerability

org.openrewrite.java.security.PartialPathTraversalVulnerability

_Replaces dir.getCanonicalPath().startsWith(parent.getCanonicalPath(), which is vulnerable to partial path traversal attacks, with the more secure dir.getCanonicalFile().toPath().startsWith(parent.getCanonicalFile().toPath()).

To demonstrate this vulnerability, consider "/usr/outnot".startsWith("/usr/out"). The check is bypassed although /outnot is not under the /out directory. It's important to understand that the terminating slash may be removed when using various String representations of the File object. For example, on Linux, println(new File("/var")) will print /var, but println(new File("/var", "/") will print /var/; however, println(new File("/var", "/").getCanonicalPath()) will print /var._

Tags

• CWE-22

Source

GitHub, Issue Tracker, Maven Central

• groupId: org.openrewrite.recipe
• artifactId: rewrite-java-security
• version: 2.0.1

Example

{% tabs %} {% tab title="A.java" %}

Before

{% code title="A.java" %}

import java.io.File;
import java.io.IOException;

class A {
    void foo(File dir, File parent) throws IOException {
        if (!dir.getCanonicalPath().startsWith(parent.getCanonicalPath())) {
            throw new IOException("Invalid directory: " + dir.getCanonicalPath());
        }
    }
}

{% endcode %}

After

{% code title="A.java" %}

import java.io.File;
import java.io.IOException;

class A {
    void foo(File dir, File parent) throws IOException {
        if (!dir.getCanonicalFile().toPath().startsWith(parent.getCanonicalFile().toPath())) {
            throw new IOException("Invalid directory: " + dir.getCanonicalPath());
        }
    }
}

{% endcode %}

{% endtab %} {% tab title="Diff" %} {% code %}

--- A.java
+++ A.java
@@ -6,1 +6,1 @@
class A {
    void foo(File dir, File parent) throws IOException {
-       if (!dir.getCanonicalPath().startsWith(parent.getCanonicalPath())) {
+       if (!dir.getCanonicalFile().toPath().startsWith(parent.getCanonicalFile().toPath())) {
            throw new IOException("Invalid directory: " + dir.getCanonicalPath());

{% endcode %} {% endtab %} {% endtabs %}

Usage

This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-java-security:2.0.1 in your build file or by running a shell command (in which case no build changes are needed): {% tabs %} {% tab title="Gradle" %} {% code title="build.gradle" %}

plugins {
    id("org.openrewrite.rewrite") version("6.1.4")
}

rewrite {
    activeRecipe("org.openrewrite.java.security.PartialPathTraversalVulnerability")
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-java-security:2.0.1")
}

{% endcode %} {% endtab %} {% tab title="Maven POM" %} {% code title="pom.xml" %}

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>5.2.4</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.java.security.PartialPathTraversalVulnerability</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-java-security</artifactId>
            <version>2.0.1</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

{% endcode %} {% endtab %}

{% tab title="Maven Command Line" %} {% code title="shell" %} You will need to have Maven installed on your machine before you can run the following command.

mvn -U org.openrewrite.maven:rewrite-maven-plugin:run \
  -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-java-security:RELEASE \
  -Drewrite.activeRecipes=org.openrewrite.java.security.PartialPathTraversalVulnerability

{% endcode %} {% endtab %} {% endtabs %}

Contributors

• Jonathan Leitschuh
• Knut Wannheden
• Patrick
• Jonathan Schnéider

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