CVE-2023-27350

CRITICAL9.8

CISA KEV

Published 2023-04-20 · Updated 2026-06-17 · Source zdi-disclosures@trendmicro.com

Summary

CVE-2023-27350 is a critical-severity (CVSS 9.8) vulnerability in PaperCut MF/NG. CISA added it to the Known Exploited Vulnerabilities catalog on April 21, 2023, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by May 12, 2023. CISA also lists it as known to be used in ransomware campaigns, so it should be prioritised accordingly. PaperCut has 5 vulnerabilities in the KEV catalog, 2 of them linked to ransomware.

All 5 known-exploited PaperCut vulnerabilities →

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.

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

CWE-284

CISA Known-Exploited Vulnerability

Product: PaperCut — MF/NG

Name: PaperCut MF/NG Improper Access Control Vulnerability

Date added: 2023-04-21 · Due: 2023-05-12

USED IN RANSOMWARE

Required action: Apply updates per vendor instructions.

References

View on NVD

More exploited PaperCut vulnerabilities

Most recently added to CISA KEV

CVE-2026-82078
NG/MF — PaperCut NG/MF Unsafe Reflection Vulnerability
added 2026-08-31
CVE-2026-81578
NG/MF — PaperCut NG/MF Missing Authentication for Critical Function Vulnerability
added 2026-08-31
CVE-2023-27351
RANSOMWARE
NG/MF — PaperCut NG/MF Improper Authentication Vulnerability
added 2026-04-20
CVE-2023-2533
NG/MF — PaperCut NG/MF Cross-Site Request Forgery (CSRF) Vulnerability
added 2025-07-28

View all →

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