vuln-fix: Zip Slip Vulnerability (openmrs#4144)

This fixes a Zip-Slip vulnerability.

This change does one of two things. This change either

1. Inserts a guard to protect against Zip Slip.
OR
2. 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())`.

For number 2, 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`.

Weakness: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Severity: High
CVSSS: 7.4
Detection: CodeQL (https://codeql.github.com/codeql-query-help/java/java-zipslip/) & OpenRewrite (https://public.moderne.io/recipes/org.openrewrite.java.security.ZipSlip)

Reported-by: Jonathan Leitschuh <[email protected]>
Signed-off-by: Jonathan Leitschuh <[email protected]>

Bug-tracker: JLLeitschuh/security-research#16

Co-authored-by: Moderne <[email protected]>

Co-authored-by: Moderne <[email protected]>

web/src/main/java/org/openmrs/web/filter/initialization/TestInstallUtil.java

@@ -184,9 +184,14 @@ protected static boolean addZippedTestModules(InputStream in) {
 
 					//delete all previously added modules in case of prior test installations
 					FileUtils.cleanDirectory(moduleRepository);
+
+					final File zipEntryFile = new File(moduleRepository, fileName);
+
+					if (!zipEntryFile.toPath().normalize().startsWith(moduleRepository.toPath().normalize())) {
+						throw new IOException("Bad zip entry");
+					}
 
-					OpenmrsUtil.copyFile(zipFile.getInputStream(entry), new BufferedOutputStream(new FileOutputStream(
-				        new File(moduleRepository, fileName))));
+					OpenmrsUtil.copyFile(zipFile.getInputStream(entry), new BufferedOutputStream(new FileOutputStream(zipEntryFile)));
 				} else {
 					log.debug("Ignoring file that is not a .omod '{}'", fileName);
 				}