# CVE-2023-27350: PaperCut MF/NG Improper Access Control

> Remote attackers can bypass authentication to execute arbitrary code with SYSTEM privileges in PaperCut NG.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 21 Apr 2023 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Apr 2023
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-cfg6-7x4x-p3pj

## What is CVE-2023-27350?

CVE-2023-27350 is a critical authentication bypass vulnerability in PaperCut NG, published on 20 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The specific flaw exists within the SetupCompleted class. The issue results from improper access control. An attacker can leverage this vulnerability to bypass authentication and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-18987.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2023-27350?

It affects 2 products.


Products: Papercut Papercut Mf, Papercut Papercut Ng.

## How do I fix CVE-2023-27350?

No fix has been published for CVE-2023-27350 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 12 May 2023.

## Is CVE-2023-27350 being exploited?

Yes. Attackers have exploited CVE-2023-27350 in the wild since at least 21 Apr 2023, including in ransomware campaigns.

Public exploit code:

- Proof of Concept Exploit for PaperCut CVE-2023-27350 (github_poc): https://github.com/horizon3ai/CVE-2023-27350
- https://github.com/imancybersecurity/CVE-2023-27350-POC (github_poc): https://github.com/imancybersecurity/CVE-2023-27350-POC
- Exploit for Papercut CVE-2023-27350. [+] Reverse shell [+] Mass checking (github_poc): https://github.com/adhikara13/CVE-2023-27350
- A simple python script to check if a service is vulnerable (github_poc): https://github.com/MaanVader/CVE-2023-27350-POC
- Unauthenticated remote command execution in Papercut service allows an attacker to execute commands due to improper access controls in the SetupCompleted Java class. (github_poc): https://github.com/monke443/CVE-2023-27350
- Perfom With Massive Authentication Bypass In PaperCut MF/NG (github_poc): https://github.com/Ap0dexMe0/CVE-2023-27350

## Other vulnerabilities in PaperCut NG

- [CVE-2026-82078](https://insights.sbomify.com/CVE-2026-82078/): PaperCut NG/MF Unsafe Reflection (critical 9.4, exploited in the wild)
- [CVE-2026-81578](https://insights.sbomify.com/CVE-2026-81578/): PaperCut NG/MF Missing Authentication for Critical Function (high 8.8, exploited in the wild)
- [CVE-2023-2533](https://insights.sbomify.com/CVE-2023-2533/): PaperCut NG/MF Cross-Site Request Forgery (CSRF) (high 8.4, exploited in the wild)
- [CVE-2023-27351](https://insights.sbomify.com/CVE-2023-27351/): PaperCut NG/MF Improper Authentication (high 8.2, exploited in the wild)
- [CVE-2023-39143](https://insights.sbomify.com/CVE-2023-39143/): Path traversal in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-27350 and fix it if it is affected.

What it is: CVE-2023-27350 is a critical authentication bypass vulnerability in PaperCut NG, published on 20 Apr 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2023-27350 in the wild since at least 21 Apr 2023, including in ransomware campaigns.

Affected product: PaperCut NG. 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-2023-27350/ (Markdown: https://insights.sbomify.com/CVE-2023-27350/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-27350
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-27350
- OSV: https://osv.dev/vulnerability/CVE-2023-27350

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-27350/
Summaries are generated and may contain mistakes; the official description above is the record.