Fix open redirects in Java and Spring Boot
==========================================

Refuse backslashes and control characters, then parse next with java.net.URI:
return "redirect:" + next only for a path that starts with exactly one slash,
or an https URL whose host is in an exact allowlist with no port or user info;
otherwise redirect to a fixed page. Never trust startsWith("/") or a host
substring test.

Page: https://softwaresecurity.com/fix/open-redirect/java-spring/

What is in this archive
-----------------------
open-redirect/java-spring/   the project: three implementations of the same code and one test suite
  src/main/java/com/example/login/impl/VulnerableLoginRedirect.java   (vulnerable)
  src/main/java/com/example/login/impl/FixedLoginRedirect.java   (fixed)
  src/main/java/com/example/login/impl/WrongLoginRedirect.java   (a plausible fix that still fails)
run-all.mjs   runs the tests in all three modes and checks the results (Node.js only)
LICENSE-CODE.txt

Run it
------
  Tested with OpenJDK 21.0.12.1 (Homebrew), Maven 3.9.16. run-all.mjs needs
  Node.js 22 or later. Supported versions:
  https://softwaresecurity.com/fix/versions/

  From the open-redirect/java-spring folder, install the dependencies once (this
  needs network access):

    mvn -B -q test

  Then run the tests. IMPL chooses the implementation the tests load:

    # every test passes
    IMPL=fixed mvn -B -o -q test
    # an exploit test fails
    IMPL=vulnerable mvn -B -o -q test
    # a test fails
    IMPL=wrong mvn -B -o -q test

  The JUnit report is written to target/surefire-reports/TEST-*.xml. To run all
  three modes and check the results in one step, run the harness from this top
  folder (it needs only Node.js; --install runs the install step first):

    node run-all.mjs --install open-redirect/java-spring
    node run-all.mjs open-redirect/java-spring

Verified
--------
  11 October 2026 on macOS 27.0 (Darwin 27.0.0, arm64), with jdk OpenJDK
  21.0.12.1, maven 3.9.16, springBoot 4.1.1, springFramework 7.0.9, tomcat
  11.0.26, jackson 3.1.7, junitJupiter 6.0.3, semgrep 1.180.0. Versions and
  results hold for that date: run the tests with your own versions before
  relying on the fix.

Licence
-------
  The code is MIT licensed (LICENSE-CODE.txt). The page text is CC BY 4.0.
