The 25-year-old was inside her flat in Niddrie House Park in Edinburgh at around 3am on Saturday morning when she heard a group of men and women arguing on the street.
The group entered the common stair of her block and knocked at her door.
She answered and told them to leave, but was assaulted by a woman described as being white, in her late 20s and 5ft 9ins tall, with ‘droopy’ facial features, of thin build and with short dyed ginger frizzy hair.
The victim was punched and kicked her several times and had to be taken to the Royal Infirmary of Edinburgh after suffering fractures to her cheek and jaw.
A police spokesman said: “This was a vicious and entirely unprovoked assault which left the victim with serious facial injuries, and we are appealing for help in tracing the culprit.
“Anyone who saw a group of men and women arguing in Niddrie House Park in the early hours of Saturday morning, who has any information that can help our inquires, should contact police immediately.
“Similarly, anyone who recognises the description of the suspect should also get in touch.”
Anyone with any information is asked to contact Lothian and Borders Police on 0131 311 3131 or Crimestoppers in confidence and complete anonymity on 0800 555 111.