IRS finds unauthorized Web servers connected to its networks

The Internal Revenue Service found more than 1,000 unauthorized Web servers connected to its networks, leaving the agency's systems open to hackers, according to a report released on Thursday by the IRS inspector general.

Comment on this article in The Forum.In September 2007, the IRS Computer Security Incident Response Center scanned the agency's Web servers and identified 2,093 that had at least one security vulnerability. When the center matched those servers to the IRS database of registered Web sites and servers, an inventory of systems that the agency uses to perform security maintenance and apply patches, it found 1,811, or 87 percent, were not listed in the database.

Of the unregistered servers, the IRS identified 661 that were used for legitimate agency business, leaving 1,150 servers being used for potentially unauthorized activity, according to the report.

"Unauthorized servers pose a greater risk [than authorized servers] because the IRS has no way to ensure that they will be continually configured in accordance with security standards and patched when new vulnerabilities are identified," the IG wrote in the audit report. "Malicious hackers or employees could exploit the vulnerabilities on these Web servers to manipulate data or to use the servers as launch points to attack other computers connected to the network."

Officials in the IRS' Office of the Chief Information Officer said they would "identify unauthorized Web servers and create policies and procedures to prohibit them from providing data over the IRS network," the IG report stated. "Unauthorized Web servers will be disconnected, and Web sites with inappropriate content will be referred to the Treasury Inspector General for Tax Administration Office of Investigations."

In March, the center conducted a second audit to check if the servers' security holes had been patched. Of the 2,093 servers the center identified as vulnerable, 1,936 still had at least one security hole. Of those, 437 contained a high-risk vulnerability compared with 540 servers in 2007. High-risk vulnerabilities include a weak or nonexistent password requirement or a so-called buffer overflow, a security hole that an attacker exploits by sending more information than a software program can store, allowing the hacker to take control of the server. The scan also identified 699 servers with moderate-risk vulnerabilities, a drop from the 1,101 servers found to have moderate-risk vulnerability in 2007.

The IG also reported failure by the IRS to properly authorize and inventory Web software packages. IRS security policies require agency business units use only Web server products and platforms approved by the IRS' Office of Enterprise Architecture. Use of an alternative product or platform requires a written waiver.

Officials from the IRS Modernization and Information Technology Services organization said only Web software packages used within the modernized environment have been officially approved, including ones from Microsoft, IBM and Oracle. A June 2007 scan identified about 30 unauthorized Web server software packages running on servers, many of which included embedded Web software associated with hardware devices.

"While having 33 different Web server software packages might be justified, we believe that using as few products as possible would limit security risks, such as monitoring for security vulnerabilities, due to software deficiencies and patching known security vulnerabilities, and control costs, such as licensing fees, training money, and maintenance costs," the report noted.

The IG recommended the agency CIO establish ownership of the Web registration program, enforce IRS procedures to block unauthorized servers from providing data over its network, require an annual scan of Web servers and compare the scan results to the registration database. It also said the CIO should require quarterly network scans of Web servers to measure compliance and formally limit the number of approved software packages that the agency uses for business outside of its modernization program.

IRS CIO Arthur Gonzalez supported the recommendation in a written response to the report.