Shirokov parted ways with Spartak Moscow by mutual consent last month. 

The 34-year-old midfielder played for the Red Army's junior side before pursuing his professional career with a string of Russian Premier League clubs including Zenit Saint Petersburg and FC Krasnodar. 

Shirokov won two Russian Premier League titles and the 2008 UEFA Cup with Zenit. 

"I'm very happy to come home," CSKA quoted Shirokov as saying. "This is my home club, the one in which I was developed."

Shirokov, who has scored 13 goals in 52 matches for Russia's national side, will train with the club in the Spanish city of Marbella until league action resumes next month. 

CSKA currently top the league with 37 points in 18 games, three points ahead of Rostov.