The 77-year-old slammed Lohan on Twitter in a series of posts referencing the expletive Lohan painted on her nail during her sentencing.
"Lindsay Lohan is so dumb," the New York Daily News quoted Rivers as tweeting.
"Her idea of being sworn in is cursing at the judge."
Attacking the troubled starlet's infamous hard-partying history, Rivers also quipped about Lohan's "80 proof" liquid diet.
"Lindsay Lohan had 'F--- you' painted on her nails,' said Rivers.
"What people don't know is that the judge had 'Eat me you party sk---,' painted on hers," she added.
A few hours later, DJ Ronson, took to Twitter to attack the 'Piece of Work' star.
"Hey Joan Rivers. You have collagen older than Lindsay, pick on someone your own age, oh wait I guess people that old can't hear," said Ronson on her Twitter page.
Ronson's support even made Lohan to reply her ex's message and she added the note, "thank you ;) I love yams x." (ANI)