Skip to main content
Varaxon Technologies

Known exploited vulnerability · CISA KEV

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

PaperCut MF/NG contains an improper access control vulnerability within the SetupCompleted class that allows authentication bypass and code execution in the context of system.

CVE-2023-27350

Exploited in the wild. Fix this first.

CISA added it to the Known Exploited Vulnerabilities catalog on 2023-04-21: attackers are using it right now. It is known to be used in ransomware campaigns.

CISA KEV
Listed
Added 2023-04-21 · federal fix-by 2023-05-12
EPSS (30 days)
over 99.9%
Higher than 99.9% of CVEs · 2026-11-01
CVSS v3.1
9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What CISA says

PaperCut MF/NG Improper Access Control Vulnerability

Apply updates per vendor instructions.

NVD description · published 2023-04-20

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.

Full record on NVD

Got a whole scan? Scan Hub runs this check on every finding in your Nessus, Qualys, Rapid7 or OpenVAS export and ranks the report by it.

Try it free

How to check if you are exposed to CVE-2023-27350

  1. Find every PaperCut MF/NG system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
  2. Compare each version with the fixed versions in the vendor advisory below. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
  3. Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2023-27350.

US federal agencies had to fix this by 2023-05-12. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.

Affected versions

Versions the National Vulnerability Database lists as vulnerable to CVE-2023-27350. Check the vendor advisory for the exact fixed builds before you sign anything off.

ProductVulnerable versions
Papercut MFfrom 8.0 before 20.1.7; from 21.0.0 before 21.2.11; from 22.0.0 before 22.0.9
Papercut NGfrom 8.0 before 20.1.7; from 21.0.0 before 21.2.11; from 22.0.0 before 22.0.9

Timeline

  1. · Published in the National Vulnerability Database
  2. · Added to CISA's Known Exploited Vulnerabilities catalog, 1 day after it was published
  3. · Fix-by date for US federal agencies, passed 1,269 days ago

Vendor advisories and fixes

Weakness type

More exploited PaperCut vulnerabilities

CISA lists 5 exploited PaperCut vulnerabilities. The closest matches:

Keep going

Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

Cookie preferences

Essential site functions remain available whichever option you choose. Your advertising choice is saved on this site. The Scan Hub has a separate choice.

Google and Reddit may receive cookies, identifiers, browser and device information, and your network/IP information. Reject or withdraw at any time. Read the Privacy Policy.