...
You must be inside the United States to apply for an SSN. We If you are a new student, we recommend that you wait 48 hours after receiving your Continued Attendance I-20 before you apply for an SSN.
...
Valid passport
I-94 arrival record printout
Continued Attendance I-20 printed in color ink*
Employment Verification Social Security Memo with original signatureSocial Security Letter from ISS with original signaturesignatures from your hiring department and ISSS
Social Security Number Application (SS-5 form, available for download at https://www.ssa.gov/forms/ss-5.pdf)
...