CVE-2024-0244 Overview
CVE-2024-0244 is a critical buffer overflow vulnerability affecting the CPCA PCFAX number process in Canon Office Multifunction Printers and Laser Printers. This flaw allows an attacker on the same network segment to send specially crafted data that triggers a buffer overflow condition, potentially causing the affected device to become unresponsive or enabling arbitrary code execution on the printer's embedded system.
The vulnerability impacts multiple Canon printer product lines sold globally, including the Satera MF750C Series (Japan), Color imageCLASS MF750C Series and Color imageCLASS X MF1333C (US), and i-SENSYS MF754Cdw/C1333iF (Europe), all running firmware version v03.07 and earlier.
Critical Impact
Network-accessible buffer overflow enables remote code execution on vulnerable Canon printers without authentication, potentially compromising print infrastructure and providing a foothold for lateral movement within enterprise networks.
Affected Products
- Canon i-SENSYS MF754Cdw (firmware v03.07 and earlier)
- Canon i-SENSYS X C1333iF (firmware v03.07 and earlier)
- Canon Color imageCLASS MF755Cdw (firmware v03.07 and earlier)
- Canon Color imageCLASS MF753Cdw (firmware v03.07 and earlier)
- Canon Color imageCLASS MF751Cdw (firmware v03.07 and earlier)
- Canon Color imageCLASS X MF1333C (firmware v03.07 and earlier)
- Canon LBP1333C (firmware v03.07 and earlier)
- Canon Satera MF750C Series (firmware v03.07 and earlier)
Discovery Timeline
- 2024-02-06 - CVE-2024-0244 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2024-0244
Vulnerability Analysis
This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption flaw that occurs when the CPCA PCFAX number processing component fails to properly validate input boundaries before writing data to memory buffers. The CPCA (Canon Peripheral Communication Architecture) protocol handles various printer communication functions, and the PCFAX number processing routine specifically manages fax-related number input handling.
When a malicious actor sends crafted input to the vulnerable PCFAX number process, the system writes beyond the allocated buffer boundaries, corrupting adjacent memory regions. This corruption can overwrite critical control structures, function pointers, or return addresses on the stack, enabling an attacker to redirect program execution flow.
The attack can be executed remotely over the network without requiring any authentication or user interaction, making it particularly dangerous in enterprise environments where printers are often connected to the same network segment as workstations and servers.
Root Cause
The root cause is insufficient bounds checking in the CPCA PCFAX number processing routine within the printer firmware. When handling fax number input data, the firmware fails to validate the length of incoming data against the fixed-size buffer allocated for processing. This allows attackers to supply oversized input that exceeds the buffer capacity, resulting in memory being written past the intended boundaries.
Attack Vector
The attack is network-based and can be executed by any attacker with access to the same network segment as the vulnerable printer. The exploitation requires no privileges or authentication credentials, and no user interaction is needed on the target device.
An attacker would typically perform network reconnaissance to identify vulnerable Canon printers, then send specially crafted PCFAX protocol messages containing oversized fax number data. The overflow condition corrupts memory structures, potentially allowing the attacker to either crash the printer (denial of service) or achieve code execution within the printer's embedded operating system context.
The vulnerability mechanism involves improper input validation in the CPCA PCFAX number handling routines. When processing fax destination numbers, the firmware copies user-supplied data into a fixed-size buffer without verifying that the input length does not exceed the buffer capacity. This classic buffer overflow pattern enables attackers to overwrite adjacent memory and potentially hijack execution flow. For detailed technical information, see the Canon PSIRT Advisory CP2024-001.
Detection Methods for CVE-2024-0244
Indicators of Compromise
- Unexpected printer restarts or unresponsive behavior without apparent cause
- Anomalous network traffic patterns to printer devices on CPCA/PCFAX-related ports
- Printer logs showing unusual fax processing errors or memory-related failures
- Network connections from printers to unexpected external destinations (indicating potential compromise)
Detection Strategies
- Monitor network traffic for unusually large or malformed packets destined to Canon printer devices
- Implement network intrusion detection rules to identify potential buffer overflow exploit attempts targeting printer protocols
- Track printer firmware versions across the environment to identify devices running vulnerable versions (v03.07 or earlier)
- Audit printer event logs for abnormal fax subsystem behavior or crash events
Monitoring Recommendations
- Deploy network segmentation monitoring to detect unauthorized access attempts to printer VLANs
- Establish baseline network behavior for printers and alert on deviations
- Configure SIEM rules to correlate printer-related network anomalies with potential exploitation attempts
- Implement asset inventory tracking to maintain visibility into firmware versions across all Canon printer deployments
How to Mitigate CVE-2024-0244
Immediate Actions Required
- Identify all Canon printer models in your environment that are affected by this vulnerability
- Update firmware to versions newer than v03.07 on all affected Canon printer models immediately
- Isolate vulnerable printers on dedicated network segments with restricted access until patches can be applied
- Disable PCFAX functionality if not required for business operations
Patch Information
Canon has released firmware updates to address this vulnerability. Administrators should download and apply the latest firmware from Canon's official support channels. Refer to the following vendor resources for model-specific update instructions:
- Canon PSIRT Advisory CP2024-001
- Canon USA Service Notice
- Canon Europe Security News
- Canon Japan Vulnerability Response
Workarounds
- Segment printers onto isolated VLANs with firewall rules restricting access to only authorized hosts and protocols
- Disable remote fax functionality through the printer's administration panel if the feature is not essential
- Implement network access controls to prevent unauthorized devices from communicating with printers
- Monitor and log all network traffic to and from printer devices for forensic purposes
# Network segmentation example - restrict printer VLAN access
# Example iptables rules to limit access to printer subnet
# Allow only print server to communicate with printers
iptables -A FORWARD -s 10.10.1.100 -d 10.10.50.0/24 -j ACCEPT
# Allow management workstations for firmware updates
iptables -A FORWARD -s 10.10.1.50 -d 10.10.50.0/24 -p tcp --dport 443 -j ACCEPT
# Block all other traffic to printer VLAN
iptables -A FORWARD -d 10.10.50.0/24 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
