CVE-2023-6229 Overview
CVE-2023-6229 is a critical buffer overflow vulnerability affecting the CPCA PDL Resource Download process in Canon Office Multifunction Printers and Laser Printers. This flaw allows an attacker on the same network segment to trigger denial of service conditions or execute arbitrary code on vulnerable devices. The vulnerability impacts multiple Canon printer product lines sold globally, including the Satera series (Japan), Color imageCLASS series (US), and i-SENSYS series (Europe) running firmware version v03.07 and earlier.
Critical Impact
Network-accessible buffer overflow enabling remote code execution without authentication on enterprise printing infrastructure
Affected Products
- Canon Color imageCLASS LBP674C/X LBP1333C firmware v03.07 and earlier (US)
- Canon Color imageCLASS MF750C Series/X MF1333C Series firmware v03.07 and earlier (US)
- Canon i-SENSYS LBP673Cdw/C1333P/MF750C Series/C1333i Series firmware v03.07 and earlier (Europe)
- Canon Satera LBP670C Series/MF750C Series firmware v03.07 and earlier (Japan)
- Canon MF755CDW, MF753CDW, MF751CDW, LBP674C, LBP672C, LBP671C firmware
- Canon MF455DW, MF453DW, MF452DW, MF451DW, LBP237DW, LBP236DW firmware
Discovery Timeline
- February 6, 2024 - CVE-2023-6229 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2023-6229
Vulnerability Analysis
This vulnerability resides in the CPCA (Common Peripheral Controlling Architecture) PDL (Page Description Language) Resource Download process of affected Canon printers. The flaw is classified as CWE-787 (Out-of-bounds Write), indicating that the vulnerable code writes data beyond the boundaries of allocated memory buffers during the resource download handling routine.
When processing specially crafted PDL resource download requests, the firmware fails to properly validate input boundaries, allowing attackers to overwrite adjacent memory locations. This memory corruption can lead to device instability, denial of service, or in more severe cases, complete control over the printer's execution flow enabling arbitrary code execution.
The network-accessible nature of this vulnerability is particularly concerning for enterprise environments where printers are often deployed on shared network segments with minimal segmentation from user workstations.
Root Cause
The root cause stems from insufficient bounds checking in the CPCA PDL Resource Download handler. When the firmware processes incoming resource data, it fails to validate that the data length fits within the allocated buffer space before writing. This classic buffer overflow condition (CWE-787: Out-of-bounds Write) allows memory corruption beyond the intended storage area.
The vulnerability exists in the firmware's handling of PDL resources, which are used for font management, form overlays, and other print job resources. The lack of proper input validation in this critical network-facing component creates an exploitable attack surface.
Attack Vector
The attack vector is network-based, requiring the attacker to have access to the same network segment as the vulnerable printer. Exploitation does not require authentication, user interaction, or elevated privileges, making it particularly dangerous in enterprise environments.
An attacker can exploit this vulnerability by:
- Identifying vulnerable Canon printers on the network through service discovery
- Crafting malicious PDL resource download requests with oversized or specially structured data
- Sending the malicious requests to the printer's network service handling CPCA PDL operations
- Triggering the buffer overflow to cause denial of service or execute arbitrary code
The vulnerability mechanism involves malformed input being processed by the CPCA PDL Resource Download handler without proper bounds validation. When the firmware attempts to copy or process the oversized resource data, it overwrites memory beyond the allocated buffer, potentially corrupting adjacent data structures or overwriting return addresses on the stack. For detailed technical information, refer to the Canon PSIRT Advisory CP2024-001.
Detection Methods for CVE-2023-6229
Indicators of Compromise
- Unexpected printer crashes, reboots, or unresponsive states without apparent cause
- Anomalous network traffic patterns targeting printer ports from internal network sources
- Unusual PDL resource download activity or malformed print job submissions
- Printer firmware integrity warnings or unexpected configuration changes
Detection Strategies
- Monitor network traffic to printers for anomalous PDL resource download requests with unusual payload sizes
- Implement network intrusion detection signatures for known CPCA protocol anomalies
- Deploy endpoint detection on network segments to identify exploitation attempts against printing infrastructure
- Conduct regular firmware version audits to identify devices running vulnerable versions (v03.07 and earlier)
Monitoring Recommendations
- Enable logging on network infrastructure to capture traffic patterns to/from printer devices
- Configure SIEM alerts for repeated connection attempts or error conditions on printer network ports
- Implement network segmentation monitoring to detect lateral movement toward printer VLANs
- Deploy SentinelOne Singularity for network visibility and threat detection across printing infrastructure
How to Mitigate CVE-2023-6229
Immediate Actions Required
- Update all affected Canon printer firmware to versions newer than v03.07 immediately
- Isolate vulnerable printers on dedicated network segments with restricted access controls
- Disable unnecessary network services on printers until patching is complete
- Implement firewall rules to restrict printer access to authorized hosts only
Patch Information
Canon has released firmware updates to address this vulnerability. Organizations should obtain the latest firmware from Canon's official support channels:
- Canon PSIRT Advisory CP2024-001 - Official security advisory with patch information
- Canon USA Service Notice - US region firmware updates
- Canon Europe Security News - European region updates
- Canon Japan Vulnerability Response - Japan region updates
Workarounds
- Implement network segmentation to isolate printers from general user networks
- Configure access control lists (ACLs) on network switches to restrict which hosts can communicate with printers
- Disable direct network printing and route print jobs through secured print servers where possible
- Enable printer firmware integrity verification features if available on your device model
# Network segmentation example - restrict printer VLAN access
# Configure on your network switch/firewall
# Allow only print server to access printer VLAN
iptables -A FORWARD -s 10.0.1.0/24 -d 10.0.10.0/24 -p tcp --dport 9100 -j ACCEPT
iptables -A FORWARD -s 10.0.1.100 -d 10.0.10.0/24 -j ACCEPT
iptables -A FORWARD -d 10.0.10.0/24 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
