Campus police on Monday issued an alert to students and staff about the attack, which occurred at about 12:15 p.m. Saturday in the women's locker room at the Wellness Center on the campus, located at 50 Phelan Ave.
A victim was in a shower stall when the suspect, who was hiding in an adjacent stall, climbed underneath and grabbed her, police said.
The suspect tried to cover the victim's mouth to stop her from screaming, but the woman was able to yell and struggled with the suspect, who then fled, according to police.
The suspect was described as a black man around 25 to 30 years old, about 5 feet 11 inches to 6 feet tall, and 180 pounds, with black hair. At the time of the attack, he was wearing short dark pants, black tennis shoes, and had a towel around his head, police said.
Anyone with information about the attack is asked to call CCSF police at (415) 239-3200.
Police will be meeting with Wellness Center staff to review safety protocols and set up additional safety patrols in the area.