Logan was in the city's Tahrir Square on Friday after Egyptian president Hosni Mubarak stepped down when she, her team and their security "were surrounded by a dangerous element amidst the celebration," CBS said in a statement Tuesday.
The network described a mob of more than 200 people "whipped into a frenzy."
Separated from her crew in the crush of the violent pack, she suffered what CBS called "a brutal and sustained sexual assault and beating." She was saved by a group of women and an estimated 20 Egyptian soldiers, the network said. The Associated Press does not name victims of a sexual assault unless the victim agrees to it.
She reconnected with the CBS team and returned to the U.S. on Saturday.
The scene last Friday in Tahrir Square - ground zero of 18 days of protests that brought down Mubarak - was primarily one of celebration - people wept, jumped for joy, cheered and hugged one another. Some soldiers stationed at the square ran into the crowd, and the protesters lifted them onto their shoulders. Other troops stayed at their posts, watching in awe. There were fireworks, the sound of car horns and even some shots fired in the air.
Sexual harassment of women is an all-too-common occurrence on the streets of Cairo. But many women noted a complete absence of it in the early days of protests in Tahrir Square, where demonstrators made a point of trying to create a microcosm of the society without many of Egypt's social ills.
However, in the final days, and especially after the battles with pro-Mubarak gangs who attacked the protesters in Tahrir, women noticed sexual assault had returned to the square. On the day Mubarak fell, women reported being groped by the rowdy crowds. One witness saw a woman slap a man after he touched her. The man was then passed down a line of people who all slapped him and reprimanded him.
The attack on Logan, CBS News' chief foreign affairs correspondent, was one of at least 140 others suffered by reporters covering the unrest in Egypt since Jan. 30, according to the Committee to Protect Journalists. An Egyptian reporter died from gunshot wounds he received during the protests.
A week before Friday's attack, Logan was detained by the Egyptian military for a day, along with a CBS producer and cameraman. They returned to the U.S. after their release, and Logan went back to Cairo shortly before Mubarak left.
Logan joined CBS News in 2002. She regularly reports for the "CBS Evening News" as well as "60 Minutes," where she has been a correspondent since 2006. She has reported widely from Iraq and Afghanistan, and other global trouble spots.
CBS said it had no further comment on Logan's assault.