The U.S. Internal Revenue Service continues to have "pervasive" information security weaknesses that put taxpayer information at risk, and it has made limited progress in fixing dozens of problems the U.S. Government Accountability Office has previously identified, according to a GAO report released Tuesday.

The IRS, the tax-collecting arm of the U.S. government, has "persistent information security weaknesses that place [it] at risk of disruption, fraud or inappropriate disclosure of sensitive information," the GAO report said. The agency, which collected about US$2.7 trillion in taxes in 2007, has fixed just 29 of 98 information security weaknesses identified in a report released last March, the new report said.

"Information security weaknesses -- both old and new -- continue to impair the agency's ability to ensure the confidentiality, integrity and availability of financial and taxpayer information," the GAO report said. "These deficiencies represent a material weakness in IRS's internal controls over its financial and tax processing systems."

The GAO has issued multiple reports blasting IRS information security in recent years.

The latest report described an IRS data center that took more than four months to install critical patches to server software.

At one IRS data center, about 60 employees had access to commands that would allow them to make "significant" changes to the operating system, the GAO said. At two data centers, administrator access to a key application contained unencrypted data log-ins, potentially revealing users names and passwords.

Three IRS sites visited by GAO auditors had computers or servers with poor password controls, the GAO said. Inactive user accounts were not deleted within six months, in violation of IRS policy, and some user passwords on Unix systems did not meet length or complexity requirements.

The IRS also had lax physical security controls in place for protecting IT facilities, the GAO report said. One data center allowed at least 17 workers access to sensitive areas when their jobs didn't require it, the GAO said. That same center did not always remove physical access authorizations from workers who no longer needed it. In March, that data center had identified 54 employees who no longer needed access, but in June, 29 of those employees still had access to the sensitive areas.

The IDG News Service is a Network World affiliate.