The credit card numbers of an undisclosed number of students at the University of Southern California (USC) have been exposed.

How many victims? Undisclosed.

What type of personal information? Credit card numbers, though the university said no personally identifiable information was exposed.

What happened? A breach in a third-party software system that the university installed three years ago to process credit card transactions led to the exposure of data related to purchases made at a number of the campus dining establishments – including Ronald Tutor Campus Center, Seeds, the Lab on Figueroa Street and Starbucks on the health sciences campus.

What was the response? A letter was published Thursday on the university's website explaining that the breach occurred between May 21 (possibly earlier) and June 21. The university informed the vendor of the exposure and requested it take "appropriate corrective actions to secure its system."

The Los Angeles Police Department and USC's Department of Public Safety are investigating. The university is advising students to carefully check their credit card receipts going back months for anomalous activity.

Source: KABC-TV, Los Angeles, "USC warns of credit card security breach on campus," June 29, 2012