Officials say the IRS has fixed only 29 of 98 weaknesses in its information security controls, which if left untouched could threaten the reliability of taxpayer and financial data, Federal Computer Week reported.

The backlog of information security controls weaknesses is a result of the IRS reacting slowly to an agency-wide information security program that would make sure that controls are effectively established and maintained, the U.S. Government Accountability Office said in a report after a recent GAO evaluation of IRS data security.

"As a result, IRS is at increased risk of unauthorized disclosure, modification or destruction of financial and taxpayer information," Gregory Wilshusen, GAO's information security issues director, said in a statement.

Despite recent IRS upgrades for user identification controls, the development of security for key financial systems and upgraded servers among other improvements, officials say the IRS has not resolved approximately 70 percent of potential identified weaknesses.

"We recognize that there is significant work to be accomplished to address our information security deficiencies, and we are taking aggressive steps to correct previously reported weaknesses and improve our overall information security program," Linda Stiff, acting IRS commissioner, recently said in a written statement.