Class Loading Vulnerability in Artemis

Impact

This affects all Artemis users who test Java assignments. Ares is not required. Students code that gets automatically tested can run arbitrary code in the container, or arbitrary code on the machine of an assessor in case of manual correction.

Patches

The problem cannot be resolved easily in Ares itself. Use the Maven Enforcer Plugin as follows:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-enforcer-plugin</artifactId>
    <version>3.0.0</version>
    <executions>
        <execution>
            <id>enforce-no-student-code-in-trusted-packages</id>
            <phase>process-classes</phase>
            <goals>
                <goal>enforce</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <rules>
            <requireFilesDontExist>
                <files>
                    <!-- ADD HERE THE RULES ARES TELLS YOU ARE MISSING -->
                </files>
            </requireFilesDontExist>
        </rules>
    </configuration>
</plugin>

This fails the build if student classes reside in such packages that Ares trusts. Trusted packages added in Ares using @AddTrustedPackage should be added as well.

For more information

If you have any questions or comments about this advisory:

• Open a discussion https://github.com/ls1intum/Ares/discussions
• Open an issue in https://github.com/ls1intum/Ares/issues
• Email us, see https://github.com/ls1intum/Ares/security/policy

References

See the assignment of Julius that passes the tests in TUM Artemis course: "Test - Praktikum: Grundlagen der Programmierung (Testkurs für Tutoren) - Security Tests" (if that still exists in 2022).

Also see #15 for almost the same problem.