Analysis & Opinions - Foreign Affairs

Why the NSA Makes Us More Vulnerable to Cyberattacks

| May 30, 2017

The Lessons of WannaCry


"There is plenty of blame to go around for the WannaCry ransomware that spread throughout the Internet earlier this month, disrupting work at hospitals, factories, businesses, and universities. First, there are the writers of the malicious software, which blocks victims’ access to their computers until they pay a fee. Then there are the users who didn’t install the Windows security patch that would have prevented an attack. A small portion of the blame falls on Microsoft, which wrote the insecure code in the first place. One could certainly condemn the Shadow Brokers, a group of hackers with links to Russia who stole and published the National Security Agency attack tools that included the exploit code used in the ransomware. But before all of this, there was the NSA, which found the vulnerability years ago and decided to exploit it rather than disclose it.

All software contains bugs or errors in the code. Some of these bugs have security implications, granting an attacker unauthorized access to or control of a computer. These vulnerabilities are rampant in the software we all use. A piece of software as large and complex as Microsoft Windows will contain hundreds of them, maybe more. These vulnerabilities have obvious criminal uses that can be neutralized if patched. Modern software is patched all the time—either on a fixed schedule, such as once a month with Microsoft, or whenever required, as with the Chrome browser.

When the U.S. government discovers a vulnerability in a piece of software, however, it decides between two competing equities. It can keep it secret and use it offensively, to gather foreign intelligence, help execute search warrants, or deliver malware. Or it can alert the software vendor and see that the vulnerability is patched, protecting the country—and, for that matter, the world—from similar attacks by foreign governments and cybercriminals. It’s an either-or choice. As former U.S. Assistant Attorney General Jack Goldsmith has said, “Every offensive weapon is a (potential) chink in our defense—and vice versa.”

This is all well-trod ground, and in 2010 the U.S. government put in place an interagency Vulnerabilities Equities Process (VEP) to help balance the tradeoff. The details are largely secret, but a 2014 blog post by then President Barack Obama’s cybersecurity coordinator, Michael Daniel, laid out the criteria that the government uses to decide when to keep a software flaw undisclosed. The post’s contents were unsurprising, listing questions such as “How much is the vulnerable system used in the core Internet infrastructure, in other critical infrastructure systems, in the U.S. economy, and/or in national security systems?” and “Does the vulnerability, if left unpatched, impose significant risk?” They were balanced by questions like “How badly do we need the intelligence we think we can get from exploiting the vulnerability?” Elsewhere, Daniel has noted that the U.S. government discloses to vendors the “overwhelming majority” of the vulnerabilities that it discovers—91 percent, according to NSA Director Michael S. Rogers.

The particular vulnerability in WannaCry is code-named EternalBlue, and it was discovered by the U.S. government—most likely the NSA—sometime before 2014. The Washington Post reported both how useful the bug was for attack and how much the NSA worried about it being used by others. It was a reasonable concern: many of our national security and critical infrastructure systems contain the vulnerable software, which imposed significant risk if left unpatched. And yet it was left unpatched..."

For more information on this publication: Please contact Cyber Security Project
For Academic Citation: Schneier, Bruce.“Why the NSA Makes Us More Vulnerable to Cyberattacks.” Foreign Affairs, May 30, 2017.

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