CVE-2023-26065
📋 TL;DR
This CVE describes an integer overflow vulnerability in certain Lexmark devices that could allow remote code execution. Attackers could exploit this to take control of affected printers and multifunction devices. Organizations using vulnerable Lexmark devices through February 2023 are affected.
💻 Affected Systems
- Lexmark printers and multifunction devices
📦 What is this software?
Lp Firmware by Lexmark
Lp Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
Lr Firmware by Lexmark
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full control of device, installs persistent malware, pivots to internal network, and exfiltrates sensitive print data.
Likely Case
Device compromise leading to denial of service, unauthorized access to print jobs, and potential lateral movement within network.
If Mitigated
Limited to device disruption if network segmentation and access controls prevent exploitation attempts.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with network attack vector and no privileges required. Integer overflows often lead to RCE in embedded systems.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware versions after 2023-02-19
Vendor Advisory: https://publications.lexmark.com/publications/security-alerts/CVE-2023-26065.pdf
Restart Required: Yes
Instructions:
1. Check device firmware version via web interface or display panel. 2. Download latest firmware from Lexmark support site. 3. Upload firmware via web interface or USB. 4. Apply update and restart device. 5. Verify new firmware version.
🔧 Temporary Workarounds
Network segmentation
allIsolate printers on separate VLAN with restricted access
Access control
allDisable unnecessary services and restrict management interface access
🧯 If You Can't Patch
- Remove devices from internet-facing networks immediately
- Implement strict firewall rules to allow only necessary traffic to/from devices
🔍 How to Verify
Check if Vulnerable:
Check device firmware date via web interface (Settings > Device Information) - if date is 2023-02-19 or earlier, device is vulnerable.Check Version:
Check via web interface or device display panel under Settings > Device InformationVerify Fix Applied:
Confirm firmware date is after 2023-02-19 and version has been updated.📡 Detection & Monitoring
Log Indicators:
- Unusual network connections to printer ports
- Firmware modification attempts
- Crash logs from printer services
Network Indicators:
- Unexpected traffic to printer management ports (typically 80, 443, 9100)
- Exploit pattern traffic to embedded web services
SIEM Query:
source_ip=printer_management_interface AND (status_code=500 OR bytes_transferred>threshold)