Software security provider McAfee revealed July 14 that it fixed a serious flaw in its enterprise security package Common Management Agent in January 2006 with a regular update (v3.5.5) and didn't even realize it.

Common Management Agent is McAfee's flagship technology for managing protective software in large organizations.

John Viega, McAfee's chief security architect, told eWEEK that a successful exploit of the security flaw would allow an attacker to place arbitrary files on the machine running the indicated software.

The flaw also could let a hacker seize control of a computer and steal data or delete files, Viega said.

"When the problem existed, a hacker could basically use an agent on the same network to write to virtually any kind of file he wanted, even full applications, like Microsoft Word," Viega said. "Someone could have replaced a file with a Trojan horse, for example."

However, Viega said, no customers reported any problems, and the problem went unknown until the week of July 3, when a consultancy, eEye Digital Security in Aliso Viejo, Calif., called McAfee to report what it had found in the older software, Viega said.

eEye Digital Security decided to post an advisory on its finding July 13, Viega said, and so McAfee, based in Santa Clara, Calif., followed with its revelation July 14.

"The flaw only affected the client side of the application, not the server side," Viega told eWEEK.

McAfee's engineering team had inadvertently closed the vulnerability loophole in January 2006 when his team released one of its regular program updates, Common Management Agent Update 3.5.5.

Read the full story on eWEEK.com: McAfee Says it Unwittingly Fixed Software Loophole