Dot-gov site security erodes during shutdown

Dozens of .gov sites are vulnerable because of expired security certificates caused by the partial government shutdown, according to a British internet services company.

Webpages at agencies such as NASA, the U.S. Department of Justice, and the Court of Appeals have expired TLS certificates, according to British-based Netcraft in a Jan. 10 blog post.

A Transport Layer Security certificate functions as a site's validation that it is what it says it is, as well as authorizing Public Key Infrastructure encryption for communications between the site's host server and browsers.

The certificates have to be renewed every one or two years with the trusted certificate authority that issued them. GoDaddy is such a provider.

The affected sites include government payment portals and remote access services at agencies that are shuttered because of the shutdown.

Netcraft cited a page at the Department of Justice's website with an expired certificate that rendered it inaccessible. The page's TLS has not been renewed since it expired on Dec. 17, just days before the government shutdown began.

To compound the Justice Department’s TLS problem, Netcraft said all of the Justice department's domain and subdomains are included in preloaded lists of acceptable domains on popular browsers, such as Chrome and Firefox. The expired TLS certificate now blocks the browsers from the more secure HTTPS sites.

Users can bypass the default blocks, but doing so could render users vulnerable to man in the middle cyberattacks, according to Netcraft.

The company warned that as the shutdown wears on, the problem of expired TLS certificates will only get worse.

"As more and more certificates used by government websites inevitably expire over the following days, weeks -- or maybe even months -- there could be some realistic opportunities to undermine the security of all U.S. citizens," the company said.