Some Brother printers (such as the HL-L8360CDW v1.20) were affected by a heap buffer overflow vulnerability as the IPP service did not parse attribute names properly. This would allow an attacker to execute arbitrary code on the device.
https://support.brother.com/g/b/faqend.aspx?c=us&lang=en&prod=group2&faqid=faq00100670_000