Just how bad is the security of the TSA's PervScan® machines?

They run on Windows 98.  I'm not making this up:

KASPERSKY SECURITY ANALYST SUMMIT 2014 -- Punta Cana, Dominican Republic -- A widely deployed carry-on baggage X-ray scanner used in most airports could easily be manipulated by a malicious TSA insider or an outside attacker to sneak weapons or other banned items past airline security checkpoints.

Billy Rios, director of threat intelligence at Qualys, here today said he and colleague Terry McCorkle purchased a secondhand Rapiscan 522 B X-ray system via eBay and found several blatant security weaknesses that leave the equipment vulnerable to abuse: It runs on the outdated Windows 98 operating system, stores user credentials in plain text, and includes a feature called Threat Image Projection used to train screeners by injecting .bmp images of contraband, such as a gun or knife, into a passenger carry-on in order to test the screener's reaction during training sessions. The weak logins could allow a bad guy to project phony images on the X-ray display.

But fear not, Citizen.  The TSA is staffed by professionals.  And Government processes will ensure that the outcome is over determined:

"This reminded me a lot of voting machines. When you design these government systems under procurement rules, you end up using old stuff. No one is paying attention to updating it, so security is crap because no one is analyzing it," says Bruce Schneier, CTO of Co3 Systems. "Stuff done in secret gets really shoddy security ... We know what gives us security is the constant interplay between the research community and vendors."

Yeah, good luck with that here.

"These bugs are actually embarrassing. It was embarrassing to report them to DHS -- the ability to bypass the login screen. These are really lame bugs," Rios says.

Wonder if they're going to put him on the No-Fly list now.