CVE-2023-27351

Name: CVE-2023-27351
Creator: NVD / NIST
Published: 2023-04-20T16:15:07.723+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10Actively ExploitedEPSS 78.42%

Last modified Jun 17, 2026

CVE-2023-27351 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 78.42% chance of exploitation in the next 30 days.

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

7.5/10

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

EPSS Probability

78.42%

99.5th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by May 4, 2026.

Weakness Enumeration

CWE-287

Affected Software

Vendor	Product	Versions
Papercut	Papercut Mf	>= 15.0, < 20.1.7
Papercut	Papercut Mf	>= 21.0.0, < 21.2.11
Papercut	Papercut Mf	>= 22.0.0, < 22.0.9
Papercut	Papercut Ng	>= 15.0, < 20.1.7
Papercut	Papercut Ng	>= 21.0.0, < 21.2.11
Papercut	Papercut Ng	>= 22.0.0, < 22.0.9

References

https://www.papercut.com/kb/Main/PO-1216-and-PO-1219Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-23-232/Third Party Advisory, VDB Entry
https://www.papercut.com/kb/Main/PO-1216-and-PO-1219Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-23-232/Third Party Advisory, VDB Entry
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351US Government Resource

Timeline

Published: Apr 20, 2023
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2023-27351?

How severe is CVE-2023-27351?

CVE-2023-27351 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 78.42% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2023-27351?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-27351?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST