The 24-year-old seam bowler took 5 for 54 as Leicestershire slumped to 126 for 7 at one stage before Michael Kasprowicz and Matthew Brimson staged a fightback.
It was Cawdron's third five-wicket haul in as many games following his 5 for 35 on his debut against Hampshire and 5 for 54 against Northamptonshire.
Worcestershire suffered a double blow with the abandonment of the first day of their match against Lancashire at New Road.
Time is now running out for them to qualify for next year's First Division and for their fast bowler Alamgir Sheriyar to reach 100 wickets for the season.
"It's all very frustrating," said their coach, Bill Athey. "Unfortunately we are in a position where we need to play desperately."Reuse content