While a successful downgrade restores the ability to use third-party ink, it introduces significant attack vectors. The HP 8620 is a sophisticated network node running a Linux-based kernel (HP’s Chai platform).
4.1 Known Vulnerabilities (CVEs) Older firmware versions are susceptible to known exploits. Specifically, the 8620 was affected by vulnerabilities cataloged as:
Downgrading the printer removes patches applied for these CVEs, turning the printer into a potential pivot point for attackers to access the wider network.
4.2 Network Exposure A compromised printer can be used to exfiltrate data, launch Denial of Service (DoS) attacks, or serve as a "watchdog" on the network traffic passing through it. In a corporate environment, using a downgraded printer violates standard patch management policies and compliance frameworks (such as ISO 27001 or NIST guidelines). hp officejet pro 8620 firmware downgrade
If the update fails: The utility will show an error like "Firmware older than current version cannot be installed." This means HP has locked the bootloader on your printer – you cannot downgrade. Some advanced users have attempted using a "downgrade package" via the printer's hidden Service Menu, but that is extremely risky and not recommended.
HP has removed old firmware from their official website. You must search trusted third-party communities:
Always scan downloaded files for viruses before proceeding. While a successful downgrade restores the ability to
Do not enroll in HP Instant Ink or HP ePrint. These services will force a firmware validation check.
End of document.
Here’s a concise, balanced review regarding the HP OfficeJet Pro 8620 firmware downgrade process, based on common user experiences and technical considerations. Downgrading the printer removes patches applied for these
Downgrading the firmware on the HP 8620 is non-trivial. Unlike consumer routers, printers generally do not advertise rollback capabilities in the standard menu. The process requires specific file manipulation and administrative access to the printer’s Embedded Web Server (EWS).
3.1 Architecture and Signing
HP printer firmware is typically delivered as a .rfu (Remote Firmware Update) file. Modern HP printers implement cryptographic signature verification; the printer will only accept firmware that has been signed by HP's private key. Consequently, users cannot modify the firmware code (e.g., to strip out the DRM) and re-flash it. Instead, "downgrading" relies on flashing an older, legitimate, signed version of the firmware released by HP.
3.2 The "Future Date" Technique A common method to bypass update restrictions involves manipulating the EWS:
3.3 Prerequisites To successfully downgrade an HP 8620, the printer generally must not be connected to HP Web Services (HP Connected), as "Web Services" often auto-provision the latest firmware, potentially overwriting the downgrade immediately.
