CVE-2019-6327 – This vulnerability allows remote attackers to e... (How to Fix)

Q: What is the severity of CVE-2019-6327?

CVE-2019-6327 has a CVSS score of 9.8 (CRITICAL). This vulnerability allows remote attackers to execute arbitrary code on affected HP printers via a buffer overflow in the IPP parser. Attackers can exploit this without authentication to potentially take full control of the device. Organizations using HP Color LaserJet Pro M280-M281 or LaserJet Pro MFP M28-M31 printers with outdated firmware are affected.

📋 TL;DR

This vulnerability allows remote attackers to execute arbitrary code on affected HP printers via a buffer overflow in the IPP parser. Attackers can exploit this without authentication to potentially take full control of the device. Organizations using HP Color LaserJet Pro M280-M281 or LaserJet Pro MFP M28-M31 printers with outdated firmware are affected.

💻 Affected Systems

Products:

HP Color LaserJet Pro M280-M281 Multifunction Printer series
HP LaserJet Pro MFP M28-M31 Printer series

Versions: All versions before v.20190419 for M280-M281, before v.20190426 for M28-M31

Operating Systems: Printer firmware only

Default Config Vulnerable: ⚠️ Yes

Notes: All network-connected devices with default IPP service enabled are vulnerable.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete device compromise, lateral movement to internal networks, and persistent backdoor installation.

🟠

Likely Case

Printer takeover for unauthorized printing, data exfiltration from scanned documents, or denial of service.

🟢

If Mitigated

Limited impact if printers are isolated on separate VLANs with strict network controls and updated firmware.

🌐 Internet-Facing: HIGH - Printers directly exposed to the internet can be exploited remotely without authentication.

🏢 Internal Only: MEDIUM - Internal attackers or malware could exploit this to pivot within the network.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Buffer overflow vulnerabilities in network services typically have low exploitation complexity when weaponized.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: v.20190419 for M280-M281, v.20190426 for M28-M31

Vendor Advisory: https://support.hp.com/us-en/document/c06356322

Restart Required: Yes

Instructions:

1. Download firmware update from HP support site. 2. Upload firmware via printer web interface or USB. 3. Reboot printer after installation.

🔧 Temporary Workarounds

Disable IPP service

all

Disable Internet Printing Protocol service if not required for operations

Network segmentation

all

Isolate printers on separate VLAN with strict firewall rules

🧯 If You Can't Patch

Segment printers on isolated network with no internet access
Implement strict firewall rules blocking all inbound traffic to printers except from authorized print servers

🔍 How to Verify

Check if Vulnerable:

Check firmware version via printer web interface: Settings > System > Firmware Version

Check Version:

Not applicable - check via printer web interface or control panel

Verify Fix Applied:

Confirm firmware version is v.20190419 or later for M280-M281, v.20190426 or later for M28-M31

📡 Detection & Monitoring

Log Indicators:

Unusual IPP protocol traffic patterns
Multiple failed connection attempts to printer port 631
Printer firmware version changes

Network Indicators:

Unusual traffic to printer port 631/TCP
Large IPP packets exceeding normal size
Traffic from unexpected sources to printers

SIEM Query:

source_ip:* dest_port:631 protocol:ipp packet_size:>1000

📊 Metadata

CVE ID: CVE-2019-6327

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-120

Published: June 17, 2019

Last Updated: November 21, 2024

🔗 References

https://support.hp.com/us-en/document/c06356322 Vendor Advisory
https://support.hp.com/us-en/document/c06356322 Vendor Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2019-6327, you might also want to check these: