There will often be someone held accountable, even if the issue isn't publicized, and that person could easily be you. Follow best practices for security, raise awareness where you can, and document the exceptions with your objections noted. It might not make the company more secure, but it likely will help you keep your job.
Let me add the following, keep copies of documents with your objections noted, off site ... it can be strange how at times those memos that could make a manager look less than able, just seem to disappear.