CVE-2024-0244: Critical Buffer Overflow in Canon Printers

CVE-2024-0244 is a critical (CVSS 9.8) buffer overflow in the CPCA PCFAX number process of some Canon office multifunction and laser printers. An attacker on the network segment could make the device unresponsive or run code. Firmware v03.07 and earlier is affected, so apply Canon's fix.

What's affected

The record lists these affected products, all on firmware v03.07 and earlier: Satera MF750C Series (sold in Japan), Color imageCLASS MF750C Series and Color imageCLASS X MF1333C (sold in the US), and i-SENSYS MF754Cdw and C1333iF (sold in Europe).

The record does not name a fixed firmware version. Canon's regional pages are listed as references, and when we tried the Canon PSIRT advisory (CP2024-001) our request was refused with a 403. We therefore cannot quote the fixed version, and the advisory should be checked for it, along with any mitigations Canon recommends for devices that cannot be updated.

One wording difference is worth knowing. The description says the attacker is on the network segment, while the CVSS vector in the record uses a network attack vector (AV:N). Plan on the stricter reading: anyone who can reach the printer on the network.

How to check if you're exposed

Find the firmware version on each device. On most Canon devices it appears in the settings menu or on the device status page. Many also show it on the remote user interface in a browser at the printer's address, if that is enabled.

Build a list of printers by sweeping your asset inventory for these model names, and ask the people who manage facilities and print for devices that IT does not track. Printers are often bought by departments and remain unmanaged for years.

Then ask where each printer is reachable from. A printer on a flat office network that every laptop and guest device can reach is more exposed than one on a segmented print VLAN. Printers should not be reachable from the internet. If any of these are, treat that as the first problem to fix.

What to do now

1. Inventory Canon printers and note model, region and firmware version.
2. Open the Canon advisory CP2024-001 and the page for your region to get the fixed firmware.
3. Update firmware on devices at v03.07 or earlier.
4. Move printers to a segmented network and block access from guest and user networks except print traffic.
5. If fax features are unused on the device, check the vendor advice for turning off the affected function.

Why it matters

The weakness class is CWE-787, an out-of-bounds write, which the description calls a buffer overflow in the CPCA PCFAX number process. CPCA is a Canon protocol, and the vulnerable code handles a fax number. Input of the wrong size can overflow a buffer, which the description says may make the product unresponsive or let an attacker run arbitrary code.

The score is 9.8 because the vector needs no privileges and no user action, and the impact on confidentiality, integrity and availability is rated high. Printers are weak spots in many networks: they run old embedded software, they are rarely patched, and they sit inside the trusted network.

The record's KEV flag is false and we found no statement of exploitation. Even so, a critical flaw reachable over the network on a device nobody watches is a good reason to move this one up the list.

Try it yourself

Click through it at your own pace, or open it full screen.

Quick check

Sources

• Canon PSIRT advisory CP2024-001 (returned 403 when fetched, listed in the record)
• Canon Japan notice
• Gold entry for CVE-2024-0244

Last reviewed: 19 October 2026.