CVE-2022-32204 - Exploiting Improper Input Verification in Huawei Printers (HWPSIRT-2022-87185)
Modern printers, especially in enterprise environments, are no longer simple document spitting machines. They’re networked computers with their own complex software stacks, which, unfortunately, also means they can have cybersecurity vulnerabilities — just like laptops or servers. In June 2022, a security researcher discovered CVE-2022-32204, a dangerous bug involving improper input verification within certain Huawei printer products.
This long-read will explain, in plain English, what this vulnerability is, how an attacker could use it, and what simple code might look like to trigger or exploit the bug. We’ll wrap up with recommendations and point you directly to the official advisory and additional references.
Type: Improper Input Verification
- Product: Certain Huawei printer models (see Huawei's Security Advisory)
Severity: Medium, can be serious in the right conditions
- Potential Impact: May cause the device to operate abnormally, potentially leading to service outage or denial of service
In Simple Terms
The printer's software doesn’t properly check — or “sanitize” — the information (input) it receives. So, a bad actor can send inappropriate data. If the printer software doesn’t handle this the right way, it could crash or behave incorrectly.
How Does Improper Input Verification Lead to Trouble?
Imagine if you ask someone for their age, but you don’t check if their answer is a number. They could say "blueberry muffin," which doesn’t make sense, and maybe your spreadsheet breaks. For printers, improper verification could mean a specially crafted network packet, a weirdly formatted print job, or malformed data sent through the printer's management interface.
Prerequisites
- Network access to the vulnerable Huawei printer (This may be local or remote, depending on the configuration).
- Knowledge of the protocol or interface through which exploit data can be sent (e.g., web management interface, printing protocol, etc.)
Send Malicious Input:
The attacker crafts input data that violates expected rules (e.g., super long strings, binary blobs where only text is expected, or injecting special characters).
Software to hang or reboot
- In rare cases, further exploitation (depending on the depth of the bug — as of now, CVE-2022-32204 is known to destabilize the software, not execute arbitrary code)
Example Code Snippet: Fuzzing the Printer Input
Warning: Only test vulnerability research on lab devices you own or have explicit permission to test against.
Here is how a security researcher might begin discovering if a printer is affected using Python and the socket library.
Let's assume the vulnerability is triggered by an unexpected value in a custom protocol on TCP port 910 (standard raw printing port):
import socket
# Replace with your printer's IP address
PRINTER_IP = '192.168.1.100'
PRINTER_PORT = 910
# Crafting malformed data
# This could be excessively long or contain invalid characters per protocol.
malicious_payload = b'\x00' * 4096 # 4KB of null bytes
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((PRINTER_IP, PRINTER_PORT))
s.sendall(malicious_payload) # Send data
# No response expected; attacker checks if printer service goes offline or stops working normally (manually or via automated monitor)
*Why does this work?*
If the Huawei printer doesn't check input size/format, dumping 4KB of unexpected data into its interface could overwhelm its input parser, causing a hang or crash.
Mitigation & Remediation
- Update Firmware: Vendors usually resolve improper input verification by fixing the code in a firmware update. Huawei has made patches available for affected models. Always download firmware only from the official Huawei site.
Huawei Security Advisory:
CVE Record:
Mitre CVE:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-32204
Conclusion
Printers are often overlooked in network security. CVE-2022-32204 is a wake-up call to treat every connected device as a potential point of failure. If you use Huawei (or any) printers in your home or office, ensuring they are up-to-date with vendor patches is crucial. Regularly check their network exposure and restrict access where possible.
For IT professionals, this is yet another reminder: printers are computers too, and they deserve the same attention to security as any workstation or server.
Timeline
Published on: 12/20/2024 03:15:06 UTC