Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Never allow '..' in OS.get_safe_dir_name(), fixes minor security concern, add unit tests for it #65755

Closed
wants to merge 1 commit into from
Closed

Never allow '..' in OS.get_safe_dir_name(), fixes minor security concern, add unit tests for it #65755

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 6 additions & 5 deletions core/os/os.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -211,11 +211,12 @@ uint64_t OS::get_embedded_pck_offset() const {

// Helper function to ensure that a dir name/path will be valid on the OS
String OS::get_safe_dir_name(const String &p_dir_name, bool p_allow_dir_separator) const {
Vector<String> invalid_chars = String(": * ? \" < > |").split(" ");
if (p_allow_dir_separator) {
// Dir separators are allowed, but disallow ".." to avoid going up the filesystem
invalid_chars.push_back("..");
} else {
// Disallow dangerous directory characters, especially '..' which can be used to traverse the filesystem.
Vector<String> invalid_chars = String(": * ? \" < > | ..").split(" ");

// Optionally, allow the directory separator so users can create subdirectories.
if (!p_allow_dir_separator) {
// Disallowed, so add it to invalid characters.
invalid_chars.push_back("/");
}

Expand Down
26 changes: 26 additions & 0 deletions tests/core/os/test_os.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -153,6 +153,32 @@ TEST_CASE("[OS] Execute") {
#endif
}

TEST_CASE("[OS] Ensure get_safe_dir_name returns safe results") {
// Path separators ('/', '\') are only allowed if the second argument is true.
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("a/b/c") == "a-b-c",
"Safe dir names should not contain directory separators, unless specified.");
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("a/b/c", true) == "a/b/c",
"Directory separators should be allowed, when specified.");
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("a\\b\\c") == "a-b-c",
"Safe dir names should not contain directory separators, unless specified.");
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("a\\b\\c", true) == "a/b/c",
"Legacy path separators should be replaced with slashes, when specified.");

// Never allow '..', it is dangerous! (whether that is an overstatement depends on the use case, but we should always be careful with user input).
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("../../secret/files.txt") == "----secret-files.txt",
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think ---- makes sense, but if someone disagrees let me know here.

Suggested change
OS::get_singleton()->get_safe_dir_name("../../secret/files.txt") == "----secret-files.txt",
OS::get_singleton()->get_safe_dir_name("../../secret/files.txt") == "secret-files.txt",

"Navigational path was not properly handled, the file system could have been traversed.");

// Allow '.' because it is still valid in dir/file names.
CHECK_MESSAGE(
OS::get_singleton()->get_safe_dir_name("some_file.txt") == "some_file.txt",
"Individual full stops '.' should be allowed, they are harmless in this context.");
}

} // namespace TestOS

#endif // TEST_OS_H