, SecurityFocus 2001-04-12
Redmond's security response chief warns the RSA Conference of the perils of open source.
The open source model tends to emphasize design and development. Testing is boring and expensive.
"Review is boring and time consuming, and it's hard," said Steve Lipner, manager of Microsoft's security response center. "Simply putting the source code out there and telling folks 'here it is' doesn't provide any assurance or degree of likelihood that the review will occur."
The comments, delivered at the 2001 RSA Conference, were a challenge to one of the tenets of open source, that 'with many eyes, all bugs are shallow.'
"The vendor eyes in a security review tend to be dedicated, trained, full time and paid," Lipner said.
Lipner argued that network administrators are better off spending their time reading log files and installing patches than poring over source code looking for security holes, and the system of 'peer review' that works well for vetting encryption algorithms, doesn't work to evaluate large pieces of software for flaws.
"An encryption algorithm is relatively simple, compared to a 40 million line operating system," Lipner argued. "And the discovery of an individual software flaw doesn't pay off much... It doesn't win anyone fame and fortune... People fix the flaw and move on."
Lipner, who oversees Microsoft's response to newly-reported security holes in its products, took the opportunity to point out "the repeated and recurring vulnerabilities in the Unix utilities BIND, WU-FTP, and so on. The repeated theme is people use this stuff, but they don't spend time security reviewing."
Making source code public also increases the risk that attackers will find a crucial security hole that reviewers missed, said Lipner. "That argument sounds like an argument for 'security through obscurity,' and I apologize. The facts are there."
Lipner slammed the open source development process, suggesting that the often-voluntary nature of creating works like the Linux operating system make it less disciplined, and less secure. "The open source model tends to emphasize design and development. Testing is boring and expensive."
By contrast, Microsoft does extensive testing on every product, and on every patch, said Lipner. "People ask us why our security patches take so long. One of the reasons they take so long is because we test them."
Lipner closed by warning that the nature of open source development may lend itself to abuse by malicious coders, who could devilishly clever 'trapdoors' in the code that escapes detection, hidden in plain sight.
Under polite questioning from the audience, Lipner acknowledged that some closed-source commercial products have been found to have trapdoors themselves.
Other conferees expressed skepticism that closed source software receives more thorough security reviews than open source code.
"Looking at products that come from commercial vendors, it seems the customer has very little guarantee that the software has been reviewed," said one conferee. "Industry has not acquitted itself well."