Juniper Systems announced the discovery of unauthorized code in the ScreenOS software that underlies the NetScreen line of devices. As a result of this discovery, the company announced a pair of separate vulnerabilities. The vulnerability is particularly insidious and generally messed up, says Matthew Green. Green: “On the technological awesomeness scale it rates about a two out of ten, maybe a step above hit the guy with a wrench He says he’s fortunate to know some of the right kind of people, like Steve Checkoway, who I was able to watch them work.”]
Source: https://blog.cryptographyengineering.com/2015/12/22/on-juniper-backdoor/