A 27-year-old skier from Tyumen covered the distance of 10 km in 21 minutes 31.6 seconds.
Sorina lost 0.8 seconds to race winner Jessica Diggins of the USA.
Silver went to Frida Karlsson (+0.5) from Sweden.
Earlier it was reported that Alexander Bolshunov won silver in the mass start at the Tour de Ski in Oberstdorf.