CVE-2023-27351
High 7.5 Exploited in the wild (KEV) Used in ransomware campaigns
Confirmed active exploitation — CISA KEV catalog
- Name
- PaperCut NG/MF Improper Authentication Vulnerability
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
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 SecurityRequestFilter class. The issue results from improper implementation of the authentication algorithm. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-19226.
Metrics
- CVSS 3.1
-
7.5 (HIGH)
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 78% (percentile: 100) as of 2 November 2026
- CWE
- CWE-287
Affected products
papercut: papercut mf; papercut: papercut ng
References
- https://www.papercut.com/kb/Main/PO-1216-and-PO-1219 Vendor Advisory
- https://www.papercut.com/kb/Main/PO-1216-and-PO-1219 Vendor Advisory
- https://www.zerodayinitiative.com/advisories/ZDI-23-232/ Third Party AdvisoryVDB Entry
- https://www.zerodayinitiative.com/advisories/ZDI-23-232/ Third Party AdvisoryVDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023… US Government Resource