HP 發了安全通告「HPSBPI02728 SSRT100692 rev.2 - Certain HP Printers and HP Digital Senders, Remote Firmware Update Enabled by Default」，在安全通告內列出的印表機都有安全問題，「允許遠端安裝未經授權的印表機韌體」，攻擊者可以遠端直接安裝有木馬的韌體：
A potential security vulnerability has been identified with certain HP printers and HP digital senders. The vulnerability could be exploited remotely to install unauthorized printer firmware.
另外可以參考 CVE-2011-4161 的說明：
The default configuration of the HP CM8060 Color MFP with Edgeline; Color LaserJet 3xxx, 4xxx, 5550, 9500, CMxxxx, CPxxxx, and Enterprise CPxxxx; Digital Sender 9200c and 9250c; LaserJet 4xxx, 5200, 90xx, Mxxxx, and Pxxxx; and LaserJet Enterprise 500 color M551, 600, M4555 MFP, and P3015 enables the Remote Firmware Update (RFU) setting, which allows remote attackers to execute arbitrary code by using a session on TCP port 9100 to upload a crafted firmware update.
能更新的就想辦法更新吧，無法更新的看看有沒有辦法處理 port 9100...