An incorrect update to Symantec's Norton security software on Wednesday blocked Internet access for some America Online users.
The issue affected AOL customers using recent editions of Norton AntiVirus and Norton Internet Security, Symantec said in a statement sent via e-mail on Thursday. The culprit was an update to intrusion prevention software that is part of the security software, the company said.
"This update incorrectly detected traffic patterns used as part of the AOL connection as a potential risk," Symantec said in the statement. AOL has about 20 million Internet service subscribers.
As a result of the incorrect update, AOL dial-up customers lost their connection and AOL broadband users were unable to access AOL servers, Symantec said. The erroneous update was removed from Symantec's servers about seven hours after it was released, and a corrected version was posted, the company said.
The Norton problem is the second high-profile problem with security software within a week. Last Friday an error in McAfee's virus definition file caused the company's consumer and enterprise antivirus products to flag Microsoft's Excel, as well as other applications on users' PCs, as a virus called W95/CTX.
Norton users who are experiencing problems can contact Symantec customer service at 1-800-927-3991 at no cost or read more on the issue at the company's Web site. Symantec advises users who are unable to go online because of the issue to disable their Norton software, connect to the Internet and immediately download updated definition files.