You can see shias often quoting this book.
Aga Buzurg Tahrani in his “Zaria” said:
و ان لم يعلم تشيعه لكنه غنوصى و الكتاب يعد من كتب الشيعة
Even though the Shiasm of the author is not known, but he is Gnostic, and the Book is considered to be one of the books of Shia”
See “Zariya” 25 /p 290