CVE-2023-27971

Q: What is the severity of CVE-2023-27971?

CVE-2023-27971 has a CVSS score of 9.8 (CRITICAL). This CVE describes a critical buffer overflow vulnerability in certain HP LaserJet Pro printers that could allow remote attackers to execute arbitrary code or gain elevated privileges. Affected organizations using vulnerable HP printer models are at risk of complete device compromise.

9.8 CRITICAL

Remote Code Execution Buffer Overflow

📋 TL;DR

This CVE describes a critical buffer overflow vulnerability in certain HP LaserJet Pro printers that could allow remote attackers to execute arbitrary code or gain elevated privileges. Affected organizations using vulnerable HP printer models are at risk of complete device compromise.

💻 Affected Systems

Products:

HP LaserJet Pro printers (specific models listed in HP advisory)

Versions: Various firmware versions prior to patched releases

Operating Systems: Printer firmware

Default Config Vulnerable: ⚠️ Yes

Notes: Affects specific HP LaserJet Pro models with vulnerable firmware versions. Check HP advisory for exact model list.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

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

🟠

Likely Case

Printer compromise allowing attackers to intercept print jobs, access network credentials, or use the device as a foothold for further attacks.

🟢

If Mitigated

Limited impact with proper network segmentation and access controls, potentially only affecting printer functionality.

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

🏢 Internal Only: MEDIUM - Internal attackers or malware could exploit this to gain foothold in the network.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

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

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Firmware updates specified in HP Security Bulletin

Vendor Advisory: https://support.hp.com/us-en/document/ish_7919962-7920003-16/hpsbpi03839

Restart Required: Yes

Instructions:

1. Visit HP support site and download latest firmware for your printer model. 2. Upload firmware via printer web interface or HP tools. 3. Reboot printer after update completes.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate printers on separate VLAN with restricted access

Disable Unnecessary Services

all

Turn off unused network services on printer (FTP, Telnet, etc.)

🧯 If You Can't Patch

Segment printers on isolated network with strict firewall rules
Disable remote management features and limit access to trusted IPs only

🔍 How to Verify

Check if Vulnerable:

Check printer firmware version via web interface and compare against HP's patched versions list

Check Version:

Access printer web interface at http://[printer-ip] and navigate to Information or Settings page

Verify Fix Applied:

Confirm firmware version matches or exceeds patched version from HP advisory

📡 Detection & Monitoring

Log Indicators:

Unusual network connections to printer services
Multiple failed connection attempts followed by successful exploit patterns

Network Indicators:

Unexpected traffic to printer ports (9100, 631, 80, 443)
Anomalous payload sizes in printer protocol communications

SIEM Query:

source_ip=* dest_ip=[printer_ip] (port=9100 OR port=631) AND (bytes_sent>threshold OR pattern="buffer_overflow_indicators")

📊 Metadata

CVE ID: CVE-2023-27971

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: April 28, 2023

Last Updated: January 30, 2025

🔗 References

https://support.hp.com/us-en/document/ish_7919962-7920003-16/hpsbpi03839 Vendor Advisory
https://support.hp.com/us-en/document/ish_7919962-7920003-16/hpsbpi03839 Vendor Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Laserjet Pro M304 M305 W1a46a Firmware by Hp

Laserjet Pro M304 M305 W1a47a Firmware by Hp

Laserjet Pro M304 M305 W1a48a Firmware by Hp

Laserjet Pro M304 M305 W1a66a Firmware by Hp

Laserjet Pro M404 M405 93m22a Firmware by Hp

Laserjet Pro M404 M405 W1a51a Firmware by Hp

Laserjet Pro M404 M405 W1a52a Firmware by Hp

Laserjet Pro M404 M405 W1a53a Firmware by Hp

Laserjet Pro M404 M405 W1a56a Firmware by Hp

Laserjet Pro M404 M405 W1a57a Firmware by Hp

Laserjet Pro M404 M405 W1a58a Firmware by Hp

Laserjet Pro M404 M405 W1a59a Firmware by Hp

Laserjet Pro M404 M405 W1a60a Firmware by Hp

Laserjet Pro M404 M405 W1a63a Firmware by Hp

Laserjet Pro M453 M454 W1y40a Firmware by Hp

Laserjet Pro M453 M454 W1y41a Firmware by Hp

Laserjet Pro M453 M454 W1y43a Firmware by Hp

Laserjet Pro M453 M454 W1y44a Firmware by Hp

Laserjet Pro M453 M454 W1y45a Firmware by Hp

Laserjet Pro M453 M454 W1y46a Firmware by Hp

Laserjet Pro M453 M454 W1y47a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a29a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a30a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a32a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a34a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a35a Firmware by Hp

Laserjet Pro Mfp M428 M429 F W1a38a Firmware by Hp

Laserjet Pro Mfp M428 M429 W1a28a Firmware by Hp

Laserjet Pro Mfp M428 M429 W1a31a Firmware by Hp

Laserjet Pro Mfp M428 M429 W1a33a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a75a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a76a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a77a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a78a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a79a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a80a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a81a Firmware by Hp

Laserjet Pro Mfp M478 M479 W1a82a Firmware by Hp