# CVE-2021-20872: Security feature bypass in bizhub series

> A physical attacker can bypass firmware integrity checks to install malicious firmware on Konica Minolta bizhub devices.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jan 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8vf2-m489-q377

## What is CVE-2021-20872?

CVE-2021-20872 is a medium-severity vulnerability in KONICA MINOLTA, INC. bizhub series, published on 4 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Protection mechanism failure 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 C3851FS/C3851/C3351 GC9-X4 and earlier, bizhub 4752/4052 GC9-X4 and earlier) allows a physical attacker to bypass the firmware integrity verification and to install malicious firmware.

## Which versions are affected by CVE-2021-20872?

It affects 52 products.


Products: Konicaminolta Bizhub 224e Firmware, Konicaminolta Bizhub 227 Firmware, Konicaminolta Bizhub 284e Firmware, Konicaminolta Bizhub 287 Firmware, Konicaminolta Bizhub 308 Firmware, Konicaminolta Bizhub 308e Firmware, Konicaminolta Bizhub 364e Firmware, Konicaminolta Bizhub 368 Firmware, Konicaminolta Bizhub 368e Firmware, Konicaminolta Bizhub 4052 Firmware, Konicaminolta Bizhub 454e Firmware, Konicaminolta Bizhub 458 Firmware, Konicaminolta Bizhub 458e Firmware, Konicaminolta Bizhub 4752 Firmware, Konicaminolta Bizhub 554e Firmware, Konicaminolta Bizhub 558 Firmware, Konicaminolta Bizhub 558e Firmware, Konicaminolta Bizhub 654 Firmware, Konicaminolta Bizhub 654e Firmware, Konicaminolta Bizhub 658e Firmware and 32 more.

## How do I fix CVE-2021-20872?

No fix has been published for CVE-2021-20872 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20872 being exploited?

There is no known exploitation of CVE-2021-20872 in the wild and no public exploit code.

## Other vulnerabilities in KONICA MINOLTA, INC. bizhub series

- [CVE-2021-20869](https://insights.sbomify.com/CVE-2021-20869/): Information disclosure in bizhub series (medium 6.5)
- [CVE-2021-20871](https://insights.sbomify.com/CVE-2021-20871/): Information disclosure in bizhub series (medium 6.5)
- [CVE-2021-20870](https://insights.sbomify.com/CVE-2021-20870/): Information disclosure in bizhub series (medium 4.6)
- [CVE-2021-20868](https://insights.sbomify.com/CVE-2021-20868/): Missing authorization in bizhub series (medium 4.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20872 and fix it if it is affected.

What it is: CVE-2021-20872 is a medium-severity vulnerability in KONICA MINOLTA, INC. bizhub series, published on 4 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-20872 in the wild and no public exploit code.

Affected product: KONICA MINOLTA, INC. bizhub series. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-20872/ (Markdown: https://insights.sbomify.com/CVE-2021-20872/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20872
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20872
- OSV: https://osv.dev/vulnerability/CVE-2021-20872

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20872/
Summaries are generated and may contain mistakes; the official description above is the record.