CVE DATABASE / CVE-2023-27351
CVE-2023-27351
PaperCut NG/MF Improper Authentication Vulnerability
Confirmed exploited in the wild. Added 2026-04-20.
Federal remediation due 2026-05-04.
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.
Summary
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.
CVSS 3.1 breakdown
| Base score | 7.5 (HIGH) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | NONE |
| Availability | NONE |
Weakness type (CWE)
Affected products
Use our free CVE Lookup tool for the latest NVD record, or browse the full CISA KEV catalog.
References
- https://www.papercut.com/kb/Main/PO-1216-and-PO-1219
- https://www.zerodayinitiative.com/advisories/ZDI-23-232/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351
Data: NIST NVD + CISA KEV. NVD last modified 2026-04-21. Always verify against the vendor advisory before acting.