CVE-2024-12647 Overview
CVE-2024-12647 is a critical buffer overflow vulnerability affecting Canon Small Office Multifunction Printers and Laser Printers. The vulnerability exists in the CPCA (Canon Peripheral Communication Architecture) font download processing functionality. An attacker with network access to the same network segment as the vulnerable printer can exploit this flaw to cause the device to become unresponsive or achieve arbitrary code execution on the affected device.
This vulnerability impacts a wide range of Canon printer models sold across Japan, the United States, and Europe under different product names including Satera, Color imageCLASS, and i-SENSYS product lines. Firmware version v05.04 and earlier are affected.
Critical Impact
Network-accessible buffer overflow enabling remote code execution without authentication on enterprise printer infrastructure.
Affected Products
- Canon Satera MF656Cdw/MF654Cdw (Japan) - firmware v05.04 and earlier
- Canon Color imageCLASS MF656Cdw/MF654Cdw/MF653Cdw/MF652Cdw/LBP633Cdw/LBP632Cdw (US) - firmware v05.04 and earlier
- Canon i-SENSYS MF657Cdw/MF655Cdw/MF651Cdw/LBP633Cdw/LBP631Cdw (Europe) - firmware v05.04 and earlier
- Canon MF455dw/MF453dw/MF452dw/MF451dw/MF465dw/MF462dw series
- Canon LBP237dw/LBP236dw/LBP247dw/LBP246dw series
- Canon MF1238 II/MF1440/MF1643IF II/MF1643I II series
- Canon LBP1238 II/LBP1440 series
Discovery Timeline
- 2025-01-28 - CVE-2024-12647 published to NVD
- 2026-01-26 - Last updated in NVD database
Technical Details for CVE-2024-12647
Vulnerability Analysis
This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption issue that occurs when the CPCA font download processing module fails to properly validate the size or boundaries of font data being processed. When a maliciously crafted font download request is sent to the printer, the processing routine writes data beyond the allocated buffer boundaries, corrupting adjacent memory regions.
The exploitation requires network adjacency, meaning the attacker must be on the same network segment as the vulnerable printer. However, no authentication or user interaction is required to trigger the vulnerability, making it particularly dangerous in corporate network environments where printers are commonly deployed without adequate network segmentation.
Successful exploitation can result in complete compromise of the affected printer device, potentially allowing attackers to intercept print jobs containing sensitive information, use the printer as a pivot point for lateral movement within the network, or cause persistent denial of service conditions.
Root Cause
The root cause lies in insufficient bounds checking within the CPCA font download handler. When processing incoming font data, the firmware fails to validate that the data length does not exceed the size of the destination buffer. This allows an attacker to supply oversized font data that overflows the allocated memory region, potentially overwriting critical data structures or code pointers.
Attack Vector
The attack vector is network-based and requires no privileges or user interaction. An attacker on the same network segment can send specially crafted CPCA font download requests to the printer's network interface. The printer's font processing service accepts these requests and processes the malicious data without proper validation.
The attack flow involves:
- Identifying a vulnerable Canon printer on the network segment
- Crafting a malicious CPCA font download request with oversized font data
- Sending the request to the printer's network service
- The buffer overflow occurs during font processing, allowing memory corruption
- Depending on the payload, this results in denial of service or code execution
Due to the sensitive nature of this vulnerability and the absence of verified proof-of-concept code, specific exploitation details are not provided. Organizations should consult the Canon PSIRT Advisory CP2025-001 for additional technical information.
Detection Methods for CVE-2024-12647
Indicators of Compromise
- Unexpected printer reboots or unresponsive states without clear cause
- Unusual network traffic patterns to printer devices, particularly large or malformed CPCA protocol packets
- Printer configuration changes not initiated by administrators
- Anomalous outbound network connections originating from printer IP addresses
Detection Strategies
- Monitor network traffic for unusual CPCA protocol communications or oversized font download requests directed at Canon printers
- Implement network intrusion detection rules to identify potential buffer overflow exploitation attempts against printer services
- Deploy network segmentation to isolate printers and enable focused monitoring of cross-segment traffic
- Regularly audit printer firmware versions to identify devices running vulnerable firmware v05.04 or earlier
Monitoring Recommendations
- Enable logging on network devices to capture traffic to and from printer subnets
- Configure SIEM alerts for printer device anomalies such as unexpected reboots, configuration changes, or unusual network behavior
- Conduct periodic vulnerability scans of networked printer infrastructure to identify unpatched devices
- Implement asset inventory management to track Canon printer models and their firmware versions
How to Mitigate CVE-2024-12647
Immediate Actions Required
- Identify all Canon printers in your environment matching the affected models listed in this advisory
- Update firmware to versions newer than v05.04 following Canon's official guidance
- Isolate vulnerable printers on dedicated network segments with restricted access until patching is complete
- Review network access controls to limit which systems can communicate with printer devices
- Consider temporarily disabling network printing functionality for critical devices until patches are applied
Patch Information
Canon has released firmware updates to address this vulnerability. Organizations should download and apply the latest firmware from Canon's official support channels:
- Canon Japan Vulnerability Response
- Canon PSIRT Advisory CP2025-001
- Canon Europe Security News
- Canon USA Service Notice
Ensure firmware versions are updated beyond v05.04 on all affected models.
Workarounds
- Place affected printers behind firewalls or on isolated VLAN segments to prevent direct network access from untrusted systems
- Disable or restrict CPCA font download functionality if supported by the device configuration and not required for operations
- Implement network access control lists (ACLs) to limit printer access to authorized management stations and print servers only
- Use private addressing with NAT to prevent direct external access to printer devices
- Consider using direct USB connections for sensitive printing operations as a temporary measure
# Example: Network segmentation using VLAN ACL (Cisco IOS example)
# Restrict access to printer VLAN (VLAN 100) from other network segments
access-list 100 permit tcp host 10.0.1.50 10.0.100.0 0.0.0.255 eq 9100
access-list 100 permit tcp host 10.0.1.51 10.0.100.0 0.0.0.255 eq 9100
access-list 100 deny ip any 10.0.100.0 0.0.0.255
access-list 100 permit ip any any
interface Vlan100
description Printer-VLAN
ip access-group 100 in
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
