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Mf642cdw FirmwareOperating system · Canon

CVE-2023-0856

CRITICAL · 9.8 CVSS v3.1 Published 2023-05-11
Fix available
A fix is available. Upgrade to after 11.04 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Buffer overflow in IPP sides attribute process of Office / Small Office Multifunction Printers and Laser Printers(*) which may allow an attacker on the network segment to trigger the affected product being unresponsive or to execute arbitrary code. *:Satera LBP660C Series/LBP620C Series/MF740C Series/MF640C Series firmware Ver.11.04 and earlier sold in Japan. Color imageCLASS LBP660C Series/LBP 620C Series/X LBP1127C/MF740C Series/MF640C Series/X MF1127C firmware Ver.11.04 and earlier sold in US. i-SENSYS LBP660C Series/LBP620C Series/MF740C Series/MF640C Series, C1127P, C1127iF, C1127i firmware Ver.11.04 and earlier sold in Europe.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Buffer overflow vulnerability in the IPP (Internet Printing Protocol) sides attribute processing of affected Canon Satera, Color imageCLASS, and i-SENSYS multifunction printers and laser printers. An attacker on the same network segment can send specially crafted IPP requests with an overly long 'sides' attribute value that overflows a buffer, potentially causing the device to become unresponsive or allowing arbitrary code execution.

MitigationUpdate affected devices to firmware version 11.05 or later as provided by Canon. Additionally, restrict network access to printing devices by placing them behind a firewall or on a VLAN with only trusted systems, as the attack requires network adjacency.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mf642cdw FirmwareOperating system
Affected:<= 11.04
Mf644cdw FirmwareOperating system
Affected:<= 11.04
Mf741cdw FirmwareOperating system
Affected:<= 11.04
Mf743cdw FirmwareOperating system
Affected:<= 11.04
Mf745cdw FirmwareOperating system
Affected:<= 11.04
Lbp621c FirmwareOperating system
Affected:<= 11.04
Lbp622c FirmwareOperating system
Affected:<= 11.04
Lbp661c FirmwareOperating system
Affected:<= 11.04

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the printer model
    Access the printer web interface or check the device label to confirm the exact model number (e.g., MF642cdw, MF644cdw, MF741cdw, MF743cdw, MF745cdw, LBP621c, LBP622c, LBP661c).
    Affected if The model is one of the eight affected models listed in the CVE.
  2. Check the installed firmware version
    Log into the printer web interface and navigate to the Firmware Update or Device Information section to view the current firmware version. Alternatively, print a configuration page from the device menu.
    Affected if The firmware version is 11.04 or lower.
  3. Verify IPP service is enabled
    Access the printer web interface, go to the Network or Port settings, and check if IPP (Internet Printing Protocol) is enabled. Look for IPP port 631 in the active port list.
    Affected if IPP is enabled and accessible on the network.
  4. Assess network exposure
    Determine if the printer is on a shared network segment with untrusted systems. Check if the device is behind a proper firewall or on an isolated VLAN, or if it is directly accessible from a broader network.
    Affected if The printer is accessible from network segments with untrusted users or systems.

A user is affected if they have one of the eight listed Canon models running firmware version 11.04 or lower, with IPP enabled and accessible from a network segment where an attacker could send malicious IPP requests.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 11.04
Interim mitigation

Update affected devices to firmware version 11.05 or later as provided by Canon. Additionally, restrict network access to printing devices by placing them behind a firewall or on a VLAN with only trusted systems, as the attack requires network adjacency.

Recommended fix High confidence

Any Canon firmware version higher than 11.04 (check Canon support sites for the latest available firmware for your specific model)

  1. 1. Identify the exact Canon printer model from the affected product list (Mf642cdw, Mf644cdw, Mf741cdw, Mf743cdw, Mf745cdw, Lbp621c, Lbp622c, Lbp661c)
  2. 2. Access the Canon support website for your region (canon.jp, www.usa.canon.com, or www.canon-europe.com depending on where the device was purchased)
  3. 3. Navigate to the product support page for your specific printer model
  4. 4. Locate the firmware downloads section
  5. 5. Download the latest available firmware version (must be higher than version 11.04)
  6. 6. Access the printer's web administration interface or use the Canon firmware update utility
  7. 7. Upload and install the updated firmware following the on-screen instructions
  8. 8. After firmware update, verify the new firmware version in the printer settings
Caveat Firmware updates on Canon printers typically retain settings, but a power interruption during update can brick the device - ensure stable power during the update process

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mf642cdw Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-0856 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data