(IDG) -- Sony is urging some customers who have bought Vaio computers since November to upgrade their software after the discovery of a potentially serious software bug that could allow intruders access to their computers. The security advisory applies to customers in much of Asia and some Middle East and African countries.

The bug exists in the Vaio Manual or Vaio Manual CyberSupport for Vaio versions 3.0 and 3.1 online manual software that is preinstalled on some Vaio machines and on the recovery CD-ROM.

By exploiting the bug, third parties could gain access to a Vaio computer running the software via the Internet or by e-mail and then copy or overwrite data stored on the computer's hard drive without being detected by antivirus software, Sony says.