Language: Python
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
def deny_uploads_containing_script_tag(uploaded_file):
    for chunk in uploaded_file.chunks(2048):
        if chunk.lower().find(b"<script") > -1:
            raise ValidationError(_("File contains forbidden <script> tag"))

        if chunk.lower().find(b"onload=") > -1:
            raise ValidationError(_("File contains forbidden attribute:") + "onload")