There is a directory traversal issue in attachment downloads in Gmail. For non-gmail accounts, there is no path sanitization on the attachment filename in the email, so when attachments are downloaded, a file with any name and any contents can be written to anywhere on the filesystem that the Gmail app can access.
acde40f4552aa5149be44a28077696e55fd9ef012ef17e6a02fc5ba02d2dce2c