CVE-2023-27351highunder attackransomwareCWE-287

CVE-2023-27351: high-severity vulnerability in PaperCut NG

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88Vexday Risk Score

Patch now. It under exploitation confirmed by CISA and has a working public exploit.

ssvc Actcvss 8.2epss 78%
from disclosure to weapon
Published on NVDApr 20
CISA KEV+1096d
Action required by CISAfederal deadline: 2026-05-04

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

In short

PaperCut NG 22.0.5 has a flaw that allows attackers to skip the authentication process completely, gaining unauthorized access to the system without needing a password or credentials.

Technical detail

The SecurityRequestFilter class in PaperCut NG 22.0.5 (Build 63914) contains an improper authentication algorithm implementation that permits remote attackers to bypass authentication without credentials. The vulnerability is network-accessible and requires no pre-conditions, resulting in complete authentication bypass and unauthorized system access.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products
PaperCut · NG
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