The incident took place at around 7.30pm on Tuesday, February 28 in an alley off Champions Way, adjacent to Stourbridge Road.
The victim was approached by a man who said something to the victim before trying to attack her.
However, she was able to break free and go to a place of safety where she called police. The victim is being supported by specialist officers at West Mercia Police.
Detectives have been carrying out extensive enquiries to identify and arrest the suspect.
He is described as a white man, approximately 6ft 1-2in tall, medium build with dark hair cut short to the sides and longer on top.
He had facial hair which is described as being stubble length and wore a white/light grey long sleeve top. It is not known how old he was.
Investigating officer Detective Constable Claire Rees said: "We are appealing for anyone who witnessed the sexual assault or any suspicious behaviour in this area around the time of the incident to make contact with us.
"We would particularly like to hear from people who were in Champions Way, Stourbridge Road or surrounding roads around this time or anyone who may have dashcam, doorbell or CCTV footage which might have captured the man fleeing the scene.
"We have increased our patrols in the area and have been conducting areas searches alongside investigating any potential lines of enquiry. Please come forward to us with any information which you think could help our investigation, no matter how small."
Anyone with information is asked to contact North Worcestershire Reactive CID team on email: email@example.com or ring on 101 extension 773 2145.
Alternatively, information can be passed anonymously to Crimestoppers on 0800 555 111 or by visiting crimestoppers-org.uk. Crimestoppers is 100 per cent confidential.