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Findings

CVE-2023-27351

PaperCut NG/MF Improper Authentication Vulnerability

Published Apr 20, 2023 · updated Oct 1, 2026 · PaperCut NG/MF

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.

Timeline

Detection, updates, and resolution for this record.

  1. Apr 20, 2023 · Catalog

    Detected

    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 authenti

  2. Apr 20, 2026 · CISA KEV

    Known exploited

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  3. May 4, 2026 · CISA KEV

    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.

  4. Oct 1, 2026 · Catalog

    Updated

    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 authenti

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.

CISA due date May 4, 2026

Affected

  • cpe papercut/papercut mfversion unspecified
  • cpe papercut/papercut ngversion unspecified
  • vendor PaperCut NG/MFversion unspecified

Sources

  • CISA KEVCVE-2023-27351

    PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class.

    cisa.gov
  • CVE.orgCVE-2023-27351

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2023-27351

    30-day exploitation probability 78.1%

    first.org
  • NIST NVDCVE-2023-27351

    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

    nvd.nist.gov

References