Fugitive document leaker Edward Snowden's role as a systems administrator provided easy access to classified National Security Agency documents sitting in a file-sharing location on the spy agency's intranet portal.
The documents were kept in the portal so that NSA analysts and other officials could read and discuss them online, NSA CTO Lonny Anderson told National Public Radio in an interview Wednesday.
As a contracted NSA systems administrator with top-secret Sensitive Compartmented Information (SCI) clearance, Snowden could access the intranet site and move especially sensitive documents to a more secure location without raising red flags, Anderson said.
Thus, Snowden could steal the NSA Power Point slides, secret court orders and classified agency reports that he leaked to the media. "The assignment was the perfect cover for someone who wanted to leak documents," Anderson told NPR.
"His job was to do what he did. He wasn't a ghost. He wasn't that clever. He did his job," Anderson said.
Since the leaks, the NSA has taken several steps to plug such holes in its security. For instance, a new "two-person rule," which stipulates that two individuals with similar roles and authority must act together to execute specific functions, including the storing or backing up of data.
Those with privileged access to systems, like system and network administrators, are no longer anonymous on the NSA network -- all of their actions will be observable, Anderson told NPR.
The NSA has also started "tagging" sensitive data and documents to ensure that only people with a need to see a documents can access it. The document tagging rule also lets security auditors see how individuals with legitimate access to the data are actually using it, Anderson said.
While NSA employees can still access the intranet used by Snowden to steal documents, new controls won't allow such thefts to happen again, he said. "Could someone today do what [Snowden] did? No," Anderson claimed.
Anderson's revelations shed a bit more light on how Snowden could access and download tens of thousands of sensitive documents from the protected NSA systems. It's still unclear, though, how he managed to download the data onto thumb drives and take them from the workplace without being noticed.
Security experts have pointed to the Snowden caper as a classic example of how insiders, especially workers with privileged access to systems, could steal corporate data.
A survey of mostly medium-sized companies by security vendor Symplified earlier this year found that more than half had authorized network access to 250 or more external partners, contractors and consultants. About 55% of respondents said 1,500 or more employees have privileged access to corporate applications.
"Insider attacks and unauthorized access happen much more often than you may think," said Darren Platt, CTO of Symplified.
Platt said an employee, for instance, could download a customer database and take it to a competitor, a contractor could use his or her access to personnel information for personal gain, or a former employee could access applications as a corporate spy.
"Companies need to shift their thinking from an outside-in model of security to an inside out approach," said Eric Chiu, founder of Hytrust, a cloud infrastructure management company.
"Only by implementing strong access controls [like] the recent NSA 'two-man' rule as well as role-based monitoring, can you secure critical systems and data against these threats and prevent breaches as well as data center failures," he said.
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan, or subscribe to Jaikumar's RSS feed . His email address is firstname.lastname@example.org.