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Bizhub C750i FirmwareOperating system · Konicaminolta

CVE-2021-20871

MEDIUM · 6.5 CVSS v3.1 Published 2022-01-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
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
Exposure of sensitive information to an unauthorized actor vulnerability in KONICA MINOLTA bizhub series (bizhub C750i G00-35 and earlier, bizhub C650i/C550i/C450i G00-B6 and earlier, bizhub C360i/C300i/C250i G00-B6 and earlier, bizhub 750i/650i/550i/450i G00-37 and earlier, bizhub 360i/300i G00-33 and earlier, bizhub C287i/C257i/C227i G00-19 and earlier, bizhub 306i/266i/246i/226i G00-B6 and earlier, bizhub C759/C659 GC7-X8 and earlier, bizhub C658/C558/C458 GC7-X8 and earlier, bizhub 958/808/758 GC7-X8 and earlier, bizhub 658e/558e/458e GC7-X8 and earlier, bizhub C287/C227 GC7-X8 and earlier, bizhub 287/227 GC7-X8 and earlier, bizhub 368e/308e GC7-X8 and earlier, bizhub C368/C308/C258 GC9-X4 and earlier, bizhub 558/458/368/308 GC9-X4 and earlier, bizhub C754e/C654e GDQ-M0 and earlier, bizhub 754e/654e GDQ-M0 and earlier, bizhub C554e/C454e GDQ-M1 and earlier, bizhub C364e/C284e/C224e GDQ-M1 and earlier, bizhub 554e/454e/364e/284e/224e GDQ-M1 and earlier, bizhub C754/C654 C554/C454 GR1-M0 and earlier, bizhub C364/C284/C224 GR1-M0 and earlier, bizhub 754/654 GR1-M0 and earlier, bizhub C4050i/C3350i/C4000i/C3300i G00-B6 and earlier, bizhub C3320i G00-B6 and earlier, bizhub 4750i/4050i G00-22 and earlier, bizhub 4700i G00-22 and earlier, bizhub C3851FS/C3851/C3351 GC9-X4 and earlier, and bizhub 4752/4052 GC9-X4 and earlier) allows an attacker on the adjacent network to obtain the credentials if the destination information including credentials are registered in the address book via a specific SOAP message.

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 · high confidence

This vulnerability in KONICA MINOLTA bizhub series multifunction printers allows an adjacent network attacker to obtain credentials stored in the device's address book by sending a specific SOAP message. The attack exploits the address book feature where destination information including credentials can be registered, and the specific SOAP message triggers disclosure of these credentials to an unauthorized actor on the adjacent network.

MitigationUpdate affected devices to the patched firmware versions as specified in the vendor advisory. As a compensating control, restrict network access to the printer's management interfaces to trusted networks or IP ranges to prevent adjacent network attackers from reaching the vulnerable SOAP endpoint.

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
Bizhub C750i FirmwareOperating system
Affected:< g00-e9
Bizhub C650i FirmwareOperating system
Affected:< g00-e9
Bizhub C550i FirmwareOperating system
Affected:< g00-e9
Bizhub C450i FirmwareOperating system
Affected:< g00-e9
Bizhub C360i FirmwareOperating system
Affected:< g00-e9
Bizhub C300i FirmwareOperating system
Affected:< g00-e9
Bizhub C250i FirmwareOperating system
Affected:< g00-e9
Bizhub 750i FirmwareOperating system
Affected:< g00-e9

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

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 bizhub model
    Access the device's web interface or print a configuration page to confirm the exact model number (e.g., C750i, C650i, C550i, C450i, C360i, C300i, C250i, or 750i).
    Affected if The model is one of the eight affected models listed in the advisory.
  2. Check the firmware version
    In the device's web interface, navigate to the firmware or system information section. Compare the installed firmware version against 'g00-e9'. Versions below g00-e9 (e.g., g00-e8, g00-d0, etc.) are vulnerable.
    Affected if The installed firmware version is less than g00-e9.
  3. Verify the address book contains credentials
    Access the address book or destination registration feature via the web interface or device panel. Check if any stored destinations (email, SMB, FTP, etc.) have authentication credentials saved.
    Affected if The address book contains destinations with saved usernames and passwords.
  4. Assess network accessibility to SOAP endpoint
    From a system on the same network segment as the printer, verify if TCP port 80 or 443 (HTTP/HTTPS) on the printer is reachable. The vulnerability exploits a SOAP message to the address book service.
    Affected if The device management interface is accessible from untrusted network segments or adjacent systems.

You are affected if your device is one of the eight listed bizhub models running firmware version below g00-e9, has credentials stored in the address book, and is accessible from an adjacent network where an attacker could send the crafted SOAP request.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update affected devices to the patched firmware versions as specified in the vendor advisory. As a compensating control, restrict network access to the printer's management interfaces to trusted networks or IP ranges to prevent adjacent network attackers from reaching the vulnerable SOAP endpoint.

Recommended fix Moderate confidence

Firmware g00-e9 or later for affected models (specific fixed versions vary by model - refer to KONICA MINOLTA security advisory for complete version list)

  1. 1. Identify the specific Bizhub model and current firmware version by accessing the device's web interface or control panel
  2. 2. Navigate to the KONICA MINOLTA support website (www.konicaminolta.com) and locate the firmware download section for your specific model
  3. 3. Download the latest firmware version that includes the security fix ( firmware versions g00-e9 or later for C750i/C650i/C550i/C450i/C360i/C300i/C250i/750i models)
  4. 4. Follow the manufacturer's firmware update instructions, typically involving accessing the service mode or using the device's firmware update utility
  5. 5. After updating, verify the firmware version has been successfully applied
  6. 6. As a secondary mitigation, consider restricting network access to the device using firewall rules or network segmentation to limit exposure to adjacent network attackers
Caveat Firmware updates typically require device downtime and should be tested in a non-production environment first; some legacy features may be deprecated in newer firmware versions

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

Fix this in Bizhub C750i Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2021-20871 in production — separate from our analysis above.

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What this is

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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