Henry Webster, then 15, suffered three skull fractures in the attack by a group of Asian youths in 2007.
His mother Liz Webster said the review showed the school was at fault.
Mr Webster, now 18, was punched, kicked and hit with a claw hammer at Ridgeway School, in Wroughton, near Swindon. Mrs Webster said: “This review has confirmed our belief that the Ridgeway School was responsible for the horrific, devastating assault on our son which has left him with permanent injuries.
“The criticism of the local authority is tantamount to a whitewash as it is so minimal and limited.”
Before the attack, Mr Webster had agreed to fight a boy “one on one” due to peer pressure and to stop harassment he thought he and his friends were experiencing. He has returned to part-time education, but still suffers from short-term memory loss. The report summary, published by the Swindon Local Safeguarding Children Board, said: “The school, although it knew in advance, did not prepare for the arrival of a significant number of British Asian students in 2005.”more