CSC said Colossus helps insurers assess the severity of injuries, but does not make payments.

"Because the Colossus application helps insurance adjusters bring fairness and consistency to the claims process, we do not believe that consumers should be concerned about the potential for 'low-ball' claims," Ed Charlton, a vice president in CSC's property and casualty insurance division, said in an email. "Payments are negotiated between the insurance company and its claimants."

The of medical and insurance-adjusting information, he said. The software brings consistency to claims, "while still allowing the claims professional to consider and factor in unique claim attributes before determining the fair value for any individual claim," he added.

More than half of the 20 largest auto and property insurance companies in the U.S. use CSC's Colossus, and many others use similar products from competitors, Hunter said. The claims software market is largely unregulated by state insurance agencies, and "I'm convinced there are millions of Americans still at risk," he said.

CSC originally marketed Colossus as a cost-savings product, but shifted to talking about the software as a way for insurance companies to achieve consistency in claims payouts, the report said. Some insurance companies were uncomfortable with the software marketing as a money-saving package, said the report, referencing CSC materials made public against the software vendor settled in 2009.