McCaskill said she’s part of a bipartisan group of senators introducing a bill to place strict requirements on the Student and Exchange Visitor Program (SEVP) and increase oversight.

"Sham universities knowingly commit fraud, jeopardize our nation's security and abuse an otherwise worthy visa program," McCaskill said in a statement Thursday. "For too long these institutions have broken the law and gotten away with it, but it's time to put the proper safeguards in place to ensure their schemes have consequences. This bipartisan legislation is another step in working to fully secure our nation's borders and keep our communities safe."

The Student Visa Integrity Act — which hasn’t been introduced yet — would make it a criminal offense if a person makes a materially false statement or provides false information when petitioning to bring in foreign students. The bill would also limit the SEVP program to accredited schools and allow for the immediate withdrawal of a participant in the SEVP program if there’s evidence of fraud.

The GAO report warned that the fraud scheme could make the United States vulnerable to potential terrorists seeking to enter the country, such as the two 9/11 hijackers who applied for student visas to attend flight schools within the United States.

Senators called for the GAO report after it became public that a California school, Tri-Valley University, enrolled more than 1,500 foreign students until a federal investigation exposed the school as a scam. Tri-Valley officials gave student visas to undercover agents, posing as foreign nationals, who said they had no intention of attending school. The students paid $5,400 per semester in tuition to obtain the visas until the school was shut down.