CVE-2023-27351

Analyzed
Published: 20 Apr 2023, 00:00
Last modified:21 Apr 2026, 03:55

Vulnerability Summary

Overall Risk (default)
high
50/100
CVSS Score
8.2 HIGH
v3.0 (cve.org)
EPSS Score
87.73% CRITICAL
88% probability +40.53%
KEV
Listed
CISA
1 listing
Ransomware
Known Use
Public exploits
None found
Dark Web
Not detected

Timeline

20 Apr 2023, 00:00
Published
Vulnerability first disclosed
20 Apr 2026, 00:00
Added to CISA KEV
PaperCut NG/MF Improper Authentication Vulnerability
21 Apr 2026, 03:55
Last Modified
Vulnerability information updated
04 May 2026, 00:00
CISA Remediation Due
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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
  • v3.0•HIGH•Score: 8.2CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS Trends

Current EPSS score: 87.73%• Percentile: 99%

Techniques & Countermeasures

  • CWE-287•Improper Authentication

    When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Affected Systems

  • papercut•ng

    22.0.5 (Build 63914)

  • papercut•papercut_mf

    ≥ 15.0.0, < 20.1.7 | ≥ 15.0, < 20.1.7 | ≥ 21.0.0, < 21.2.11 | ≥ 22.0.0, < 22.0.9

  • papercut•papercut_ng

    ≥ 15.0.0, < 20.1.7 | ≥ 15.0, < 20.1.7 | ≥ 21.0.0, < 21.2.11 | ≥ 22.0.0, < 22.0.9

References (3)