Critical. A vulnerability whose exploitation could allow code execution without user interaction. These scenarios include self-propagating malware (e.g. network worms), or unavoidable common use scenarios where code execution occurs without warnings or prompts. This could mean browsing to a web page or opening email.
A strain is a stretching or tearing of muscle or tendon. A tendon is a fibrous cord of tissue that connects muscles to bones. Strains often occur in the lower back and in the hamstring muscle in the back of your thigh. Initial treatment for both sprains and strains includes rest, ice, compression and elevation.
Strain is defined as to exert or stretch to the maximum or to injure by too much exertion. 1  An example of strain is for a spectator to stretch over his seat to see a concert. 2  An example of strain is for a football player to pull a muscle from playing too roughly.  to draw or stretch tight.